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I- What is meant by each of the following:

1. Avogadro's number. 12. Weight percent.

2. Mole. 13. Molar concentration (mole/liter).

3. Molar mass. 14. ppm.

4. Molar volume. 15. Volumetric analysis.

5. STP. 16. Standard solution.

6. Gay – Lussac's law. 17. Titration process.

7. Avogadro's law. 18. Neutralization reactions.

8. The gas density. 19. Indicator.

9. Analytical chemistry 20. Gravimetric analysis.

10. Qualitative analysis. 21. Volatilization method.

11. Quantitative analysis. 22. Precipitation method.

23. Ashless filter paper

II - Write scientific terms:

1. The number of atoms, molecules or ions in one mole of any substance.

2. A unit of quantity that consists of 6.02 x 1023 particles.

3. The mass in grams of one mole of any pure substance.

4. The volumes of gases involved in a reaction and the gases produced

exist in fixed ratios.

5. The law which states that equal volumes of gases under identical

conditions of pressure and temperature contain equal numbers of

particles.

6. A mass per unit volume of a substance.

7. A type of chemical analysis that aims at identifying the constituents of

a mixture or compound.

8. A type of chemical analysis that aims at determining the concentration

or quantity of the constituents of a sample.



9. The weight of a substance in 100 grams of its solution.

10.The number of moles of solute per liter of solution.

11.A solution containing 1 mole of solute in 1000 mL of solution.

12.A method of quantitative analysis that is based on measurement of the

volume of the substance to be analyzed.

13.A solution of accurately known concentration.

14.A chemical process in which the concentration of a solution can be

determined by using standard solution of known concentration.

15.A reaction which is used for the determination of the concentration of

acids and bases.

16.A reaction which is used for the determination of the concentration of

redox substance.

17.A reaction which is used for the determination of the substances that

form sparingly soluble products.

18.The point at which complete reaction takes place in titration process.

19.A compound that exhibits different colours depending on the nature of

the medium.

20.A method of quantitative analysis that depends on the separation of

the analyte by volatilization or precipitation, then determining its

amount by weight.

21.A method of gravimetric analysis that is based on the volatilization of

the element or compound to be determined.

22.A type of filter papers upon ignition leaves no ash.

23.A method of gravimetric analysis that is based on precipitation of the

analyte in the form of pure sparingly soluble compound with

constant and known chemical structure.

24.The mass of matter which contains 6.02 x 1023 molecules of it.



25.The volume of the reactant gases in a chemical reaction is directly

proportional to the volume of gases produced. (2nd session 06)

26.The equal volumes of different gases contain equal numbers of

molecules (at S.T.P). (2nd session 07)

27.The number of dissolved moles in a litre of the solution.

III - Correct the underlined words:

1. One mole of sodium atoms contains 23 atoms of sodium.

2. Half mole of chlorine molecules contains 17 molecules of chlorine.

3. One mole of potassium sulphate (K2SO4) contains 54 atoms.

4. One mole of nitrate ions contains 2 nitrate ions.

5. Three moles of hydrogen ions contain 6.02x1023 ions of hydrogen.

6. Two moles of ammonia gas contain 2.41x1024 ammonia molecules.

7. Half mole of gold (19779 Au) atoms weighs 118 grams.

8. 0.05 mole of ethylene (C2H4) molecules weighs 22 grams (C=12,

H=1).

9. 6.02 x 1023 molecules of aluminum chloride weigh one gram.

(Al = 27, Cl = 35.5)

10. One mole of acetylene gas occupies a volume of one liters at STP.

11. 0.1 mole of hydrogen gas occupies 30 liters at STP.

12. 3.23 x 1023 molecules of nitrogen gas occupy 5 liters at STP.

13. 15 grams of chlorine gas occupies 2 liters at STP. (Cl = 35.5)

14. The molar mass of a gas at STP whose density is 1.96 grams/liter is

20 grams.

15. Density of a gas at STP depends on the molar volume only.

16. The density of O2 gas is equal to that of O3 gas at STP. (O = 16)

17. The concentration of 1.3 moles of sodium carbonate dissolved in

200 mL of the solution is 3M.



18. 30 grams of potassium hydroxide is dissolved in 122 mL of water to

make 6M solution. (H = 1, O = 16, K = 39)

19. One mole of potassium bromide (KBr) dissociate in water producing

3 ions.

20. The number of ions produced by dissolving 8.2 grams of sodium

sulphate in water is 18.06 ions. (S = 32, O = 16, Na = 23)

21. Quantitative analysis is used to identify the constituents of an

unknown substance.

22. A solution which contains 2 moles of solute in enough water to

make a 1 liter of solution called molar solution.

23. A mixture contains 6ppm iron (III) oxide means that every 100

grams of the mixture contain 6 milligrams of iron (III) oxide.

24. Standard solution is a solution of accurately known volume.

25. Titration process is a method of gravimetric analysis.

26. Methyl orange has yellow colour in acidic medium and blue colour

in basic medium.

27. Phenolphthalein has green colour in basic medium and blue colour

in acidic medium.

28. Litmus solution is colourless in acidic medium and yellow in basic

medium.

29. Phenolphthalein has blue colour in basic medium and yellow colour

in acidic medium.

30. Volatilization and precipitation methods are methods of qualitative

volumetric analysis.



IV - Give reason for each of the following:

1. The mole consists of a huge number of particles.

2. The number of molecules in one mole of acetic acid equals the number

of molecules in one mole of nitric acid.

3. One liter of any gas contains the same number of molecules at STP.

4. Twenty eight grams of nitrogen gas occupy the same volume of two

grams of hydrogen gas at (STP).

5. The density of any gas at STP depends only on its molar mass.

6. Hydrogen gas has the least density among gases at STP.

7. Indicators are used in the acid - base titrations.

8. Hydrochloric acid Solution can not be used to differentiate between

methyl orange indicator and litmus indicator.

9. Sodium hydroxide solution can not be used to differentiate between

bromothymol blue indicator and litmus indicator.

10.Standard solution is used in titration process.

11.Ashless filter papers are used in the chemical analysis by precipitation

method.

12.The number of atoms in 2 grams of hydrogen is equal to that of 32

grams of oxygen. [N = 1, O = 16]

13.The litre of chlorine gas contains the same number of molecules of

one litre of oxygen gas (at S.T.P)

14.The volume of 2 grams of hydrogen gas is the same of 28 grams of

nitrogen gas. [H = 1, N = 14]

15.The density of carbon dioxide gas CO2 is greater than that of oxygen

gas O2 [O = 16, C = 12]



V - Choose the alphabetical letter which represents the correct

answer for each of the following sentences:

(1) Avogadro's number equals …….,

(a) 22.4 (b) 60.2 x 1023 (c) 6.02 x 10-23 (d) 6.02 x 1023

(2) The mass of one mole of any gas is the mass of ……. .

(a) 6.02 x 1023 atoms from it (b) 22.4 litre from it

(c) molecular mass in grams (d) a, b and c

(3) Law of ....... states that "The volumes of gases involved in a reaction

and the gases produced exist in fixed ratios"

(a) Fixed ratio (b) Multiple proportions

(c) Gay -Lussac (d) AvogadroHeating

(4) In the reaction: N2O4(g) 2NO2(g)Cooling

(a) The number of reactant atoms = the number of produced atoms.

(b) The number of reactant moles = the number of produced moles.

(c) The volume of reactant gases = the volume of the produced ones.

(d) a, b and c.

(5) The standard of pressure and temperature (S.T.P) means ………..

(a) 760 cm. mercury and 273°C

(b) 760 mm. mercury and 273°K

(c) 670 mm mercury and 273°K

(d) 760 mm mercury and 273°C

(6) In the reaction of: SO3(g) + NO(g) SO2(g) + NO2(g)

both of NO and NO2 gases are equal in the ..........

(a) number of atoms, (b) volume. (c) density. (d) molar mass.

(7) The mass of one mole of the allotropic forms of sulphur is 256 gm so,

the formula of that form is ............ [S = 32]

(a) S (b) S8 (c) S32 (d) S256



(8) Ozone gas decomposes due to the effect of freons according to theequation: O3(g) 30(g) which of the following statement iscorrect............ [O = 16](a) 22.4 litres of ozone gas produce 22.4 litres of oxygen gas.(b) One mole of ozone gas produces 1 mole of oxygen gas.(c) Three moles of ozone gas produce 3 moles of oxygen gas(d) 48 gm of ozone gas produce 48 gm of oxygen gas.

(9) When hydrogen gas reacts with chlorine gas to form hydrogenchloride gas, the volume of reacting gasses is ....... the volume of gasproduced.(a) larger than (b) smaller than (c) equal to

(10) When hydrogen gas combines with oxygen gas to form watervapour, the volume of water vapour produced is ....... the volume ofreacting gases.(a) larger than (b) smaller than (c) equal to

(11) The number of hydrogen molecules in one mole of water equals .......molecules.(a) 2 (b) 6.02 x 1023 (c) 18 (d) 22.4

(12) The mole of CO2 occupies a volume of 22.4 litres and the mole ofCO occupies ........ litres.(a) 1 (b) 11.2 (c) 22.4 (d) 44.8

(13) The volume of hydrogen gas produced from the reaction:CH4(g) + H2O(v) CO(g) + 3H2(g) equals ...... litres.(a) 3 (b) 6 (c) 3 x 6.02 x 1023 (d) 67.2

(14) The equation: 2H2(g) + O2(g) 2H2O(v) explains that each.......(a) Two moles of hydrogen combine with a mole of oxygen.(b) Two moles of hydrogen atoms combine with an oxygen atom.(c) Two molecules of hydrogen combine with an oxygen atoms.(d) One mole of water vapour is formed from the reaction of anoxygen mole with excess of hydrogen gas.



(15) Two moles of H2 combine with one mole of O2 to form ........ moles

of water.

(a) 0.5 (b) 1 (c) 2 (d) 3

(16) A compound whose chemical formula is X2SO4 and its molecular

mass is 174 gm, thus the atomic mass for the element X equals .......

[S=32, O=16]

(a) 11gm. (b) 19gm. (c) 23gm. (d) 39gm.

(17) If one mole of sodium chloride is dissolved in water and completely

converts into Na+ and Cl- ions, the number of sodium ions in the

solution equals .........

(a) 0.5 x 6.02 x 1023 (b) 6.02 x 1023

(c) 2 x 60.2 x 1023 (d) 3 x 6.02 x 1023

(18) In the reaction: 2NO(g) + O2(g) 2NO2(g)

The litre of nitric oxide gas combines with ..........

(a) one litre of O2 to form one litre of NO2

(b) half a litre of O2 to form one litre of NO2

(c) two litres of O2 to form one litre of NO2

(d) half a litre of O2 to form half a litre of NO2

(19) If one mole of sodium carbonate is dissolved in water and

completely converts into 2Na+, CO3--, the number of carbonate ions in

the solution equals ........ mole(s).

(a) 1 (b) 2 (c) 6.02 x 1023 (d) 2 x 6.02 x 1023

(20) The volume of a gas divided by the number of its moles equals .........

(a) 22.4 (b) 760 (c) 273 (d) 6.02x1023

(21) The mass of one mole of calcium carbonate equals ............ Kg

[Ca=40, C=12, O=16]

(a) 10-2 (b) 10-1 (c) 102 (d) 103

(22) The mass of oxygen in 36 gm of water equals…… gm. [H=1, O=16]

a) 16 (b) 32 (c) 48 (d) 64



(23) The atomic mass of the element M in a sample whose mass is 78 gm

from the compound M(OH)3 equals............ [H = 1,0 = 16]

(a) 27 (b) 30 (c) 59 (d) 61

(24) The litre of 0.25 molar solution of caustic soda contains....... gm

of NaOH [Na = 23, O = 16, H = l]

(a) 4 (b) 10 (c) 40 (d) 160

(25) When 0.98 gm of sulphuric acid is dissolved in water to form a

solution whose 750 ml, concentration of the acid is …….

mole/litre. [H = 1, S = 32, O = 16]

(a) 0.001 (b) 1.73 (c) 0.013 (d) 735

(26) When 36 gm of magnesium combines with 14 gm of nitrogen, a

compound of ......... is formed. [N = 14, Mg = 24]

(a) Mg2N3 (b) Mg3N (c) MgN (d) Mg3N2

(27) Carbon oxide that is formed from the combination of 3.6 gm of

carbon with 4.8 gm of oxygen, its chemical formula will be ............

[C = 12, O = 16]

(a) CO (b) CO2 (c) C2O3 (d) CO3

(28) Iron oxide which is formed from the combination of 2.8 gm of iron

with 1.2 gm of oxygen, its chemical formula will be ……….

[Fe = 56, O = 16]

(a) FeO (b) Fe2O3 (c) Fe3O2 (d) Fe3O4

(29) The mass of sodium hydroxide required to prepare 100 cm3 of 0.5

mole/litre caustic soda solution equals ....... [Na =23, O =16, H= 1]

(a) 1 gram. (b) 2 grams. (c) 5 grams. (d) 20 grams.

(30) The biggest number of moles can be found in the acid in which its

volume and its concentration are …….. and ……..respectively.

(a) 0.0.1 L – 10 M (b) 0.25L – 4 M

(c) 0.l L – 1 M (d) 0.5 L – 0.05 M



(31) Ethyl alcohol C2H5OH is prepared by alcoholic fermentation of

glucose C6H12O6 according to the equation:

C6H12O6(aq) enzyme 2C2H5OH(L) + 2CO2(g) [C = 12 , O = 16 ,

H = 1] therefore, 9 gm of glucose produce …….. moles of alcohol.

(a) 0.01 (b) 0.05 (c) 0.1 (d) 0.25

(32) 16 gm of oxygen gas contain the same number of molecules of

........... gas at the. same pressure and temperature.

(a) 20 gm of neon (b)22 gm of CO2

(c) 40 gm of argon (d) 71 gm of chlorine

(33) ............ cm3 of carbon dioxide gas evolves on heating 10 gm of

calcium carbonate (at S.T.P) according to the equation:CaCO3(s) CaO(s} + CO2(g) [Ca = 40 , C = 12 , O = 16]

(a) 22400 (b) 2240 (c) 224 (d) 22.4

(34) 0.1 mole of the compound XC12 combines with 10.8 gm of water

to form the compound XC12 .nH2O, so the value of n is ............

[H = 1 , O = 16]

(a) 2 (b) 4 (c) 6 (d) 10

(35) When magnesium reacts with copper sulphate solution, each 1.2

gm of magnesium replaces 3.175 gm of copper. Thus the molar

ratio of the reacted magnesium to that of copper produced is…..

[Cu = 63.5, Mg = 24]

(a) 1 : 1 (b) l : 2 (c) 2 : 1 (d) 2 : 3

(36) 256 tons of SO2 gas which pollutes the air evolve from a power

station through one day and we get rid of it by passing it on

limestone CaCO3 according to the reaction:

2CaCO3(s), + 2SO2(g) + O2(g) 2CaSO4(s) + 2CO2(g)

therefore, the mass of limestone used per a day is ............ tons.[Ca = 40, C = 12, O = 16, S = 32]

(a) 100 (b) 200 (c) 256 (d) 400



(37) The …….. fertilizer contains the highest ratio of the nitrogen

element. [N = 14, H = 1]

(a) N2H4 (b) NH4NO3 (c) NH2CONH2 (d) (NH4)2SO4

(38) The graph …...... represents the following reaction :

2H2O 2H2 + O2

O2

moles

2

1

0 Time

(a)

O2

moles

2

1

0 Time

(b)

O2

moles

2

1

0 Time(c)

O2

moles

2

1

0 Time

(d)

(39) The kilogram contains …….. milligrams.

(a) 100 (b) 1000 (c) 106 (d) 109

(40) From the titration reactions ………

(a) neutralization (b) oxidation and reduction.

(c) precipitation. (d) a, b and c

(41) ……… is from the titration reactions between the salt solutions.

(a) Neutralization (b) Oxidation and reduction

(c) Precipitation (d) water

(42) The standard solution from …….. is used in determining the

concentration of hydrochloric acid.

(a) sodium chloride (b) sodium hydroxide

(c) nitric acid (d) water

(43) The standard solution from …….. is used to determine the

concentration of ammonium hydroxide.

(a) sodium carbonate (b) hydrochloric acid

(c) sodium chloride (d) ammonium acetate



(44) The end point of the reaction:

Na2CO3 + 2HCl 2NaCl + H2O + CO2 is at ………

(a) producing two moles of CO2 gas.

(b) producing one mole of sodium chloride.

(c) The complete reaction of two moles from HCl acid with one

mole of sodium carbonate.

(d) the complete reaction of two litres of sodium carbonate solution

with one litre of hydrochloric acid.

(45) All the following are indicators except ……..

(a) the bromophenol. (b) litmus.

(c) the phenolphthalein. (d) methyl orange.

(46) The phenolphthalein is a weak acid that ionizes in the alkaline

medium forming …….. colour.

(a) orange (b) red (c) blue (d) yellow

(47) The colour of methyl orange is yellow in the non ionized state and

is ……. In the alkaline medium.

(a) yellow (b) red (c) blue (d) colourless

(48) The litmus solution is purple in the neutral medium and it becomes

……. When it is added to sodium carbonate.

(a) red (b) blue (c) yellow (d) green

(49) The ……. is used in transferring limited amount solutions from a

container to another.

(a) indicator (b) pipette (c) burette (d) flask

(50) …….. of 0.5 molar of sodium hydroxide is required to neutralize

with 50 cm3 of 1 molar of sulphuric acid.

(a) 50 cm3 (b) 100 cm3 (c) 200 cm3 (d) 500 cm3



(51) The relation:molesacidofnumber

(litre)acidof x volumee)(mole/litrionconcentratacid

(a) equals one

(b) equalsalkalineofvolume

ionconcentratalkaline xmolesalkalineofnumber

(c) is not a constant value.

(d) equals 6.02 x 1023

(52) ……… of NaOH solution (2M) is added to 0.2 litre of FeCl3 (1M)

to get the greatest amount of Fe(OH)3 according to the following

equation: FeCl3(aq) + 3NaOH(aq) 3NaCl(aq) + Fe(OH)3(s)

(a) 0.1 litre (b) 0.2 litre (c) 0.3 litre (d) 0.6 litre

(53) The relation:

The concentration x volume (acid) = the concentration x volume

(base) is used to determine the concentration of hydrochloric acid

in the reaction ………. .

(a) 2HCl + Ca(OH)2 CaCl2 + 2H2O

(b) 6HCl + 2ª1(OH)3 2AlCl3 + 3H2O

(c) 2HCl + MgO MgCl2 + H2O

(d) HCl + KOH KCl + H2O

(54) The percentage of copper in hydrated copper sulphate CuSO4.5H2O

is ………. [Cu = 63.5, S = 32, O = 16, H = 1]

(a) less than 20% (b) from 20% to 40%

(c) from 40% to 60% (d) from 60% to 80%

(55) If the percentage of water in hydrated copper sulphate

CuSO4.5H2O equals 36% then the mass of white copper sulphate

CuSO4 in 200 gm of CuSO4.5H2O is ………

(a) 64 gm. (b) 72 gm. (c) 128 gm. (d) 144 gm.



(56) 45 gm of ammonium hydroxide whose density is 0.9 gm/ml is usedto precipitate an amount of methyl hydroxide and it can beobtained from…….(a) 40.5 ml. (b) 48 ml. (c) 50 ml. (d) 50 litres.

(57) the ionic equation ……. Expresses the reaction of sodium iodidesolution with lead nitrate solution to form sodium nitrate solutionand lead iodide precipitate.(a) Pb(NO3)2 + 2NaI PbI2(s) + 2NaNO3

(b) Pb2+(aq) + 2I(aq) PbI2(s)

(c) Pb2+(aq) + 2NO

3 (aq) + 2Na+ + 2I PbI2(s) + 2NaNO3

(d) Pb(NO3)2 + NaI PbI(s) + NaNO3

(58) How many atoms are represented in the formula Ca3(PO4)2?a- 3 b- 8 c- 12 d- 13

(59) How many molecules are there in one mole of CH4?a- 5 b- 1 c- 6.02 x 1023 d- 5 x 6.02 x 1023

(60) How many hydrogen molecules are there in one mole of hydrogengas (H2)?a- 1 b- 2 c- 6.02 x 1023 d- 2 x 6.02 x 1023

(61) How many hydrogen atoms are there in one mole of hydrogenmolecules (H2)?a- 2(6.02 x 1023) b- 6.02 x 1023 c- 2.02 d- 1.01

(62) How many atoms are there in 1 mole of water (H2O)?a- 3 b- 6.02 x 1023 c- 2(6.02 x 1023) d- 3(6.02 x 1023)

(63) The number of moles in 1.806 x 1023 atoms of copper is ………a- 1 b- 0.1 c- 0.3 d- 10

(64) How many moles of magnesium atoms are there in 7.32 x 1026

atoms?a- 1.22 x 103 moles. b- 6.02 x 103 moles.

c- 8.23 x 1026 moles. d- 4.44 x 101 moles.



(65) C3H7OH + ……… O2 ……… CO2 + ……….. H2O

One mole of C3H7OH underwent combustion as shown in the

reaction above. How many moles of oxygen were required for the

reaction?

a- 2 moles. b- 3 moles. c- 7/2 moles. d- 9/2 moles.

(66) How many moles of potassium chlorate (KCIO3) may be produced

from 2.4 moles of chlorine assuming that a sufficient amount of

potassium hydroxide is available?

3Cl2 + 6KOH 5KCl + KCIO3 + 3H2O

a- 1.20 b- 0.80 c- 7.2 d- 0.40

(67) According to the reaction opposite: H2 + I2 2HI

The number of molecules of hydrogen iodide produced from the

reaction of 0.3 mole of hydrogen molecules with a sufficient

amount of iodine is …………..

a- 3.612 x 1023 b- 7.826 x 1023

c- 24.08 x 1023 d- 12.04 x 1023

(68) From the previous reaction, the number of moles of hydrogen

iodide produced from the reaction of 1.25 mole of iodine with a

sufficient amount of hydrogen is ………

a- 2.5 moles. b- 3 moles.

c- 1.25 moles. d- 0.63 mole.

(69) How many moles of sodium metal are required to produce

1.505x1023 molecules of hydrogen gas in the following reaction?

2Na + 2HCI 2NaCI + H2

a- 1 mole. b- 2 moles.

c- 0.4 mole. d- 0.5 mole



(70) In the reaction below:

2FeSO4 Fe2O3 + SO2 + SO3

The number of sulphur trioxide molecules which are produced

from thermal decomposition of 2.6 moles of iron (II) sulphate is :

a- 6.02 x 1023 b- 7.826 x 1023 c- 24.08 x1023 d- 12.04 x 1023

(71) What is the mass of one mole (molar mass) of CaCO3?

(Ca = 40, C = 12, O = 16)

a- 68 g b- 75 g c- 82 g d- 100 g

(72) What is the molar mass of Ca(NO3)2? (Ca = 40, N = 14, O – 16)

a- 164 g b- 150 g c- 82 g d- 70 g

(73) The mass of 1 mole of nitrogen gas (N2) equals …….. (N = 14)

a- 82 g b- 42 g c- 28 g d- 14 g

(74) The mass, in grams, of 0.0790 moles of aluminum equals … (Al

= 27)

a- 21.3 g b- 2.1 g c- 21 g d- 0.213 g

(75) How many moles of calcium are there in 0.544g of calcium?

(Ca=40)

a- 0.0136 b- 0.0773 c- 0.554 d- 3.11

(76) How many moles of sucrose, C12H22O11, are there in 1222g of

sucrose? (C = 12, H = 1, O = 16)

a- 0.258 b- 1.22 c- 3.57 d- 10.8

(77) The mass of one mole of phosphorus in the vapour state is 124 grams

so, its formula in the vapour state is ……… (P = 31)

a- P b- P2 c- P4 d- P6

(78) How many moles of CaO can be produced from the thermal

decomposition of 172g of CaCO3? (Ca = 40, C = 12, O = 16)

CaCO3 CaO + CO2

a- 2.2 moles. b- 0.58 moles. c- 1.72 moles. d- 4 moles.



(79) How many moles of electrons are required to reduce 2.93g of nickel

ions from melted NiCI2? (Ni – 59)

Ni2+ + 2e- Ni

a- 0.05 b- 0.1 c- 1.0 d- 1.5

(80) Tungsten metal, used to make incandescent bulb filaments, is

produced by the following reaction:

WO3 + 3H2 W + 3H2O (W = 184, O = 16)

(81) How many grams of tungsten can be obtained from 0.0207 moles

of WO3?

a- 2.40 b- 4.21 c- 3.81 d- 4.32

(82) From the previous reaction, how many grams of tungsten can be

obtained from 20.36 grams of WO3?

a- 25.6 b- 16.15 c- 97.82 d- 6.12

(83) How many grams of carbon are present in 270 grams of glucose,

C6H12O6? (C = 12, H = 1, O = 16)

a- 120 grams. b- 18 grams c- 108 grams d- 180 grams

(84) 80.0 grams of butane burns according to the chemical equation:

2C4H10 + 1302 8CO2 + 10H2O

What mass of oxygen reacts? (C = 12, H = 1, O = 16)

a- 603.2 g b- 286.9 g c- 22.3 g d- 416 g

(85) How many gram of hydrogen gas can be produced from the

following reaction if 65g of HCI are reacted completely with a

sufficient amount of zinc?

Zn(s) + 2HCI(aq.) ZnCI2(aq.) + H2(g) (H = 1, Cl = 35.5)

a- 2.25g b- 1.78g c- 3.6g d- 7g

(86) Every 4 grams of hydrogen gas (H2) contain .......... ( H - 1)

a- 6.02 x 1023 molecules. b- 0.602 x 1023 molecules.

c- 6.02 x 1022 molecules. d- 12.04 x 1023 molecules.



(87) The mass of one sodium atom equals ................ (Na = 23)

a- 2.6 x 10-24 g. b- 3.82 x 10-23 g.

c- 1.66 x 10-24 g. d- 1.38 x 10-23g.

(88) The mass of 2.7 x 1023 atoms of silver equals ................. (Ag = 108)

: a- 84.5 g. b- 48.4 g. c- 96.8 g. d- 24.2 g.

(89) There are ......... iron atoms in a typical two-inch nail which has a

mass of 5.6 grams. (Fe = 56)

a- 0.602x1023 b- 6.02x1023 c- 60.2x1023 d- 602x1023.

(90) The mass of 7.6 x 1023 molecules of sodium carbonate (Na2CO3)

equals ........... (Na = 23, C = 12, O = 16)

a- 106 g. b- 83 g. c- 133.8 g. d- 391 g.

(91) About how many molecules of water do you drink in a glassful? (A

small glass holds about 180 cm3 1 cm3 of water has a mass of about

1 gram.) (H = 1, O = 16)

a- 0.602x1023 b- 6.02x1023 c- 60.2x1023 d- 602 x 1023

(91) The mass of 1.204 x 1024 atoms of hydrogen equals .......... (H = 1)

a- 1g. b- 2g. c- 3g. d- 4g.

(92) How many atoms are there in 34.6 g of carbon dioxide?

(C = 12, O = 16)

a- 14.20x1023 b- 12.1x1023 c- 4.73x1023 d- 0.786

(93) 2K + Br2 2KBr

From the reaction above, the number of potassium bromide

molecules produced from 20 grams potassium equals ....... (K = 39)

a- 3.09x1023 b- 6.17x1023 c- 18.52x1023 d- 9.3 x 1023

(94) The number of oxygen atoms produced from the thermal

decomposition of 13.5 grams of sodium nitrate equals ........

(Na = 23, N = 14, O = 16)

2NaNO3 2NaNO2 + O2

a- 9.56x1022 b- 3.8x1022 c- 2.86x1023 d- 1.9x1023



(95) Standard conditions (STP) are:

a- 0°C and 2 atm. b-273 K and 760 mm Hg

c- 0°C and 7.6cm Hg. d- 0 K and 760 mm Hg.

(96) The volumes of gases involved in a reaction and the gases

produced are....................

a- existing in fixed ratios. b-existing in equal volumes.

c- inversely proportional d- not related to one another.

(97) Which of the following states that: Equal volumes of gases at the

same temperature and pressure contain the same number of particles?

a- Boyle's law. b- Gay-Lussac's law.

c- Charle's law. d- Avogadro's principle.

(98) At STP, one molar volume is ..........................

a- 22.4 L. b- 32L. c- 10L d- 6.02 x 1023L

(99) How can the molar volume of a gas be defined?

a- The volume that one mole occupies at STP.

b- The volume that one gram occupies at STP.

c- The volume that one mole occupies at 100°C and 1 atm pressure.

d-The volume that one gram occupies at 100°C and 1 atm pressure.

(100) What is the volume of 2.0 moles of a gas at STP?

a- 44.8L b-22.4L c- 0.0223L. d-0.0446L

(101) The number of moles in 33.6 L of oxygen gas O2 at STP

equals.......

a- 48 moles. b- 3 moles. c- 1.5 moles. d- 32 moles.

(102) How many liters of O2 can be produced from 2 moles of KCIO3, by

decomposition of all the KCIO3? 2KCIO3 2KCI+ 3O2

a- 11.2 b- 22.4 c- 44.8 d- 67.2



(102) The number of moles of nitrogen gas required to produce 2 L of

ammonia gas at STP equals .............

N2 + 3H2 electric 2NH3spark

a- 8.9x10-2 b- 45x10-2 c- 0.36 d- 0.178

(103) If 10 L of CO gas react with a sufficient amount, of oxygen

completely, then how many liters of CO2 gas are formed?

2CO + O2 2CO2

a- 5 b- 10 c- 15 d- 20

(104) What volume, in liters, will be occupied at STP by 4g of H2? (H=1)

a- 11.2 b- 22.4 c- 33.6 d- 44.8

(105) 2 ZnS(s) + 3O2)2 2 ZnO(s) + 2 SO2(g)

If the reaction above took place at standard temperature and

pressure, then what was the volume of O2(g) required to produce

40.0 grams of ZnO(s)? (Zn = 65.4, 0 = 1 6)

a-(22.4)(3)(81.4)(2)(40.0) L. b-

(22.4)(2)(81.4)(3)(40.0) L.

c-(3)(81.4)(22.4)(2)(40.0) L. d-

(2)(81.4)(22.4)(2)(40.0) L.

(106) What is the mass, in grams, of 1L of nitrous oxide, N2O, at STP?

(N = 14, O = 16)

a- 1 b- 1.96 c- 11.2 d- 22

(107) If five liters of gas at STP have a mass of 12.5g then what is the

molar mass of the gas?

a- 12.5 g. b- 25.0 g. c- 17.5 g. d- 56.0 g.

(108) The mass of iron metal produced from the reaction of iron ore with

3.5L of carbon monoxide at STP as in the following reaction

equals ............. .

3CO + Fe2O3 C700o 2 Fe + 3CO2 (Fe = 56,-C = 12, O = 16)



a- 5.8g b-8.75g c- 2.9 g d- 17.5g

(109) One liter of oxygen gas at STP contains ........... oxygen molecules.

a- 6.02x1023 b- 12.04 x1046 c- 0.269 x 1022 d-0.54x1023

(110) How many hydrogen atoms are present in 12L of hydrogen gas at

STP?

a- 6.5 x 1023 b- 0.54 c- 2.06 x 10-23 d- 13.48 x 1024

(111) A gas at STP which contains 6.02 x 1023 atoms and forms diatomic

molecules will occupy .............

a- 11.2L b- 22.4L c- 33.6L d- 67.2L

(112) 3 Fe - 4 H2O Co500 Fe3O4 + 4H2

I- How many iron atoms are required to produce 11.5 L of H2 gas?

a- 2.32 x 10-26 b- 7.7 x 1022 c- 9.27 x 10-1 d- 14.3 x 1023

II - What is the volume of H2 gas produced from 9.03 x 1023 atoms

of iron metal?

a- 22.4L. b- 89.6L. c- 44.6L. d- 11.2L

(113) The concentration of 2moles of Na2CO3 dissolved intone liter of

equals.......................

a- 2M b- 0.5M c- 1M d- 3M

(114) The number of moles of sodium hydroxide in 25mL of its solution

whose concentration is 0.2 mole/L is ..............

a- 5x10-3 b- 5x-10-2 c- 2x10-3 d- 2x10-2

(115) Two moles of 0.8M sulphuric acid occupy ..................

a- 2.5mL b- 2.5L c- 0.4mL d- 0.4L

(116) How many grams of NaCl are dissolved in 500mL of a 0.05 M

solution of NaCl? (Na = 23, Cl = 35.5)

a- 0.05 g. b- 0.29g. c- 1.46g. d- 2.29g.



(117) What volume, in mL, of a 0.181 M solution is required to provide

0.0716 g of KMnO4? (K = 39, Mn = 55, O = 16).

a- 4.52 b- 2.50 c- 3.22 d- 3.62

(118) What is the molar concentration of barium hydroxide, Ba(OH)2, in

a solution formed by the reaction of 0.34g of barium with enough

water to give 200.0rnL of solution? (Ba= 137,0 = 16, H = 1)

Ba(s) + 2H2O(I) Ba (OH)2 (aq) + H2(g)

a- 1.2 x 10-2 b- 1.9 x 10-2 c- 9.2x 10-1 d- 6.2 x 10-1

(119) The number of molecules in 255 mL of 1.25M H2SO4 equals …….

a- 0.318 b- 1.92 x 1023 c- 1.92 x 1026 d- 318.75

(120) How many ions are produced when one mole of solution chloride

dissolves in water?

a- 2 b- 6.02 x 1023 c- 1.8 x 1024 d- 1.2 x 1024

(121) The number of moles of ions produced on dissolving 40g of

sodium sulphate is ………. (Na = 23, S = 32, O = 16)

a- 0.3 b- 0.85 c- 0.6 d- 1

(122) How many grams of sodium sulphate are dissolved in water to

produce 1.505 x 1022 sulphate ions? (Na = 23, S = 32, O = 16)

a- 35.5 b- 3.55 c- 7.1 d- 71

(123) How may ions of sodium are produced when 4.25 g of sodium

nitrate are dissolved in water? (Na = 23, N = 14, O = 16)

a- 3.01 x 1023 b- 3.01 x 1024

c- 3.01 x 1022 d- 301 x 1023

(124) How many H+ ions does a 5 M solution of HCl have in 1L?

a- 5 b- 6.02 x 1023 c- 1.204 x 1023 d- 3.01 x 1024

(125) The weight percentage of Na2CO3 in its solution is 15% thus, there

is ………. of sodium carbonate dissolved in 100 g of the solution.

a- 30 g b- 15 g c- 10 g d- 100 g



(126) What is the mass percent of boron in boric acid H3BO3?

(B = 11, O = 16, H = 1)

a- 17.74% b- 22.10% c- 38.00% d- 45.30%

(127) Iron ore is converted into pure iron by the following reaction,

which occurs at extremely high temperatures.

Fe2O3 + 3CO Co700 2Fe + 3CO2

A 1600 gram sample of iron ore reacted completely to form 560

grams of pure iron. What was the percent of Fe2O3 by mass in the

original sample?. (Fe = 56, 0 = 12, O = 16)

a- 25% b- 33% c- 50% c- 67%

(128) A sample of sodium hydroxide was exposed to atmospheric air for

a short time where it has absorbed carbon dioxide gas. When

analyzed, it is found that it contains 10 p.p.m. of Na2CO3, i.e the

amount of Na2CO3 in every kilogram of sodium hydroxide is .......

a- 10 milligrams. b- 10 grams. c-100 milligrams. d- 100 grams.

(129) Molarity equals ...........

a- moles of solute per liter of solution.

b- grams of solute per gram of solution.

c- grams of solute pelf liter of solution.

d- liters of solute per kilogram of solution.

(130) Titration is the general process of determining the ............. of an

acidic or basic solution through the use of an acid-base reaction.

a- boiling point b-density c-molarity d-polarity

(131) A solution of known molarity used in an acid-base titration is

known as a/an.........

a- aliquot. b- heterogeneous solution.

c- indicator. d- standard solution.



(132) An acid-base reaction: is called a .............. reaction.

a- combination b- neutralization

c- single- replacement d-synthesis

(133) Phenolphthalein is ............. in acidic medium and ............. in basic

medium.

a- red, colourless b- colourless red

c- red, yellow" d- yellow, red

(134) A 22.5 mL of 0.122M HCI neutralizes 30.0 mL of a KOH solution.

What is the molarity of the KOH solution?

a- 0.0915M. b- 0.163M. c- 0.00445M. d- 1.08M.

(135) What volume of 0.0500M HNO3 is required to neutralize 52.6 mL

of 0.250M LiOH?

a- 10.5ml b- 52.6mL c- 263mL d- 525mL

(136) A diprotic acid (Acid that contains two hydrogen protons (2H+) in

its molecule e.g. H2SO4) was titrated with a solution of sodium

hydroxide. For 25mL of the acid, 87.42mL of a 1.95M solution of

NaOH was required to reach the equivalent point. Which of the

following expressions is equal to the initial concentration of the

diprotic acid?

a-(1.95)(87.42)

(25) b-(25)

(1.95)(87.42)

c-(2)(25)

(87.42)(1.95) d-(87.42)(1.95)

(2)(25)

(137) If you titrate a 1M H2SO4, solution against 50mL of 1M NaOH

solution, what volume of H2SO4 will be needed for neutralization?

a- 10L. b- 0.025L. c- 25L d- 0.05L.

(138) What is the molar concentration of H2SO4 in a solution if 31 .91

mL of it is required to titrate 2.474g of Na2CO3?

(C = 12, O = 16, H = 1, Na = 23)



H2SO4+ Na2CO3(s) Na2SO4(aq) + H2O(I) + CO2(g)

a- 0.73 b- 1.122 c- 0.3657 d- 0.5222

(139) The mass of washing soda crystals before heating is 5 grams and

after strong heating and constant mass is 1.853 grams. What is the

% of water of crystallization of washing soda?

a- 0.6294% b- 62.9% c- 37% d- 0.37%

(140) The molecular formula for hydrated ferric oxide, or rust, is

generally written as: Fe2O3.xH26 because the water content in rust

can vary. If a 1 molar sample of hydrated ferric oxide is found to

contain. 108g of H2O, then what is the molecular formula for the

sample?

a- Fe2O3.H2O b- Fe2O3.3H2O c- Fe2O3.6H.O c- Fe2O3.10H2O

(141) Two grams of silver chloride were precipitated when hydrochloric

acid was added to a solution of silver nitrate. What was the mass of

silver nitrate?

AgNO3 + HCI AgCl + HNO3

(Ag = 108, N = 14, O = 16, Cl = 35.5)

a- 3g b- 5g c- 2.4g c- 7g

142- The total number of moles contained in 115gms of C2H5

a) 1 b) 1.5 c) 3 d) 2.5

143- The mass of two moles of O2 gas at STP equals.

a) 69 gms b) 96 gms c) 32 gms d) 64 gm

144- The total number of molecules contained in 0.5 mole of O2 is…….

a) 6.02 x 1023 b) 4.5 x 1023 c) 3.01 x 1023 d) 1.5 x 1023

145- The total number of molecules in 34.0 gms of NH3 equals to ……

a) 1 x 22.4 b) 2 x 22.4 c) 1 x 6.02 x 1023 d) 2x6.02x1023

146- The gas sample which contains a total of 3.01 x 1023 molecules is…

a) 71 gms Cl2 b) 2 gms of H2 c) 14 gms N2 d) 38 gms F2



147- The total ions produced from dissolving 8.7 gms K2SO4 in water is...

a) 0.602 x1023 b) 1.204 x 1023 c) 0.903x1023 d) 1.505x1023

148- The volume of 4.4 gms of CO2 at STP is ……..

a) 2.24 L b) 4.48 L c) 22.4 L d) 44.8 L

149- The total number of molecules in 11.2 L of N2 gas at STP is ...

a) 3.01 x l023 b) 6.02 x 1023 c) 14 d) 28

150- The density of oxygen gas (O2) at STP equals..........

a)L4.22

g32 b)L4.22

g16 c) 1.43g/L d) both (a) & (c)

151- The solution which contains the greatest number of moles of solute

is…..

a) 0.5L of 0.5 M b) 0.5 L of 2M c) 2 L of 0.5 M d) 2L of 2M

152- The percent by mass of carbon in CO2 is equal...

a)1244 x 100 b)

4412 x 100 c)

1228 x 100 d)

2812 x 10

153- The percent by mass of oxygen in CH3OH is.........

a) 50% b) 44.4% c) 32% d) 16%

154- 22.4 L of O2 reacted completely with an. excess amount of H2, 60L

to produce water. The volume of H2(g) left over is ...........

a) 15.4L b) 20.2 L c) 10.2 L d) 15.2L

155- The apparatus which is used to transfer 24.5 ml of dilute acid to

conical flask is ........

a) dropper b) pipette c) buret d) beaker

156- A sample of rain water turn methyl orange ...........

a) colorless b) red c) yellow d) blue

157- Sea water turn phenolphthalein ..............

a) colorless b) red c) yellow d) blue

158- Half liter of half molar solution of sodium carbonate contains

a) 1.6 g b) 26.5g c) 13.12g d) 265 g



159- 2 gm of sodium hydroxide (molecular mass = 40) are dissolved in

100 ml of the solution. The molarity is .........

a) 2 M b) 0.2 M c) 0.4 M d) 0.5 M

160- 0.1 mole of NaOH is mixed with 1.825 gms HC1. The produced

solution is.

a) acidic b) basic c) neutral

161- mass of A1(OH)3 produced on mixing 13.35g of A1C13 with 4 g of

NaOH is.......Al(OH)3.

a) 7.8 gms b) 2.6 gms c) 10.4 gms d) non-is correct

162- 5 gms of impure sample of lime stone whose concentration is 60%

is heated till it's completely decomposed. It gives ...... liters of CO2.

a) 1.12 L b) 0.672 L c) 0.336 L d) 1.344 L

163- 4 gms of sodium carbonate is mixed with 100 ml, 0.1 M HCI. The

mass of produced CO2 gas is ..........

a) 5.85 gms b) 4.415 gms c) 2.925 gms d) 2.2 gms

164- a sample of sodium hydroxide was exposed to atmospheric air for

short time while it has absorbed carbon dioxide gas, when analyzed

is found that it contains l0ppm of Na2CQ3, i.e. the amount of

Na2CO3 in every kilogram of sodium hydroxide is....

a) 10 milligrams b) 10 grams c) 100 milligrams d) 100 grams

165- Which 0.1 M solution will turn phenolphthalein pink?

a. HBr(aq) b. CO2(aq) c. LiOH(aq) d. CH3OH(aq)

166- Which solution is the most concentrated?

a) 1 mole of solute dissolved in 1 liter of solution?

b) 2 moles of solute dissolved in 3 liters of solution?

c) 6 moles of solute dissolved in 4 liters of solution?

d) 4 moles of solute dissolved in 8 liters of solution?



167- What is the total number of moles of H2SO4 needed to prepare 5.0liters of a 2.0 M solution of H2SO4?a. 2.5 b. 5.0 c. 10 d. 20

168- What is the molarity of a KF (aq) solution containing 116 grams ofKF in 1.00 liter of solution?a) 1.00M b) 2.00M c) 3.00M d) 4.00 M

169- What is the molarity of a solution that contains 0.202 mol KC1 in7.98 L solution?a. 0.0132 M b. 0.0253 Mc. 0.459 M d. 1.363 M

170- What is the molarity of a solution that contains 125 g NaCl in 4.00Lsolution?a. 0.535 M b. 8.56 Mc. 2.14 M d. 31.3 M

171- How many moles of HCI are present in 0.70 L of a 0.33 M HCIsolution?a. 0.23 mol c. 0.38 molb. 0.28 mol d. 0.47 mol

172- An NaOH solution contains 1.90 mol of NaOH, and itsconcentration is 0.555 M. What is its volume?a. 0.623 L c. 1.05 Lb. 0.911 L d. 3.42L

173- What is the molarity of an HCI solution if 50.0 mL is neutralized ina titration by 40.0 mL of 0.400 M NaOH?a. 0.200 M c. 0.320 Mb. 0.280 M d. 0.500 M

174- What is the molarity of an HCI solution if 125 mL is neutralized in atitration by 76.0 mL of 1.22 M KOH?a. 0.371 M c. 0.617 Mb. 0.455 M d. 0.742 M



175- What is the molarity of an NaOH solution if 4.37 mL is titrated by

11.1mL of 0.0904 MHNO3?

a. 0.230 M c. 0.460 M

b. 0.355 M d. 0.620 M

176- What is the molarity of an H2SO4 solution if 49.0 mL is

completely titrated by 68.4 mL of an NaOH solution whose

concentration is 0.333 M?

a. 0.116 M c. 0.465 M

b. 0.232 M d. 0.880 M

177- Calculate the molarity of a Ba(OH)2 solution if 1900 mL is

completely titrated by 261 mL of 0.505 M HNO3.

a. 0.0173 M c. 0.0322 M

b. 0.0254 M d. 0.0347 M

178- If 72.1 mL of 0.543 M H2SO4 completely titrates 39.0 mL of KOH

solution, what is the molarity of the KOH solution?

a. 0.317 M c. 1.00 M

b. 0.502 M d. 2.01 M

179- If 114 mL of 0.008 04 M NaOH completely titrates 118 mL of

H3PO4 solution, what is the molarity of the H3PO4 solution?

a. 0.002 59 M c. 0.007 77 M

b. 0.005 18 M d. 0.0105 M

180- What is the molarity of a Ba(OH)2 solution if 93.9 mL is

completely titrated by 15.3 mL of 0.247.M H2SO4?

a) 0.0101 M c. 0.0402 M

b) 0.0201 M d. 0.0805 M

181- What is the molarity of an H3P04 solution if 358 mL is completely

titrated by 876 mL of 0.0102 M Ba(OH)2 solution?

a) 0.0111 M c. 0.0250 M

b) 0.0166 M d. 0.0333 M



182- A compound whose water solution conducts electricity and turns

phenolphthalein pink is

a. HC1 c)NaOH b) HC2H3O2 d) CH3OH

183- Which solution will change red litmus to blue?

1. HCl(aq)

2. NaCl(aq)

3. CH3OH(aq)

4. NaOH(aq)

184- Which 0.1 M solution will turn phenolphthalein pink?

1. HBr(aq)

2. CO2(aq)

3. LiOH(aq)

4. CH3OH(aq)

185- A student wishes to prepare approximately 100 milliliters of an

aqueous solution of 6M HC1 using 12 M HCL Which procedure is

correct?

1. adding 50 mL of 12 M HC1 to 50 mL of water while stirring the

mixture steadily.

2. adding 50 mL of 12 M HC1 to 50 mL of water and then stirring the

mixture steadily.

3. adding 50 mL of water to 50 mL of 12 M HC1 while stirring the

mixture steadily.

4. adding 50 mL of water to 50 mL of 12 M HC1 and then stirring the

mixture steadily.

186- Which solution is the most concentrated?

1. 1 mole of solute dissolved in 1 liter of solution?

2. 2 moles of solute dissolved in 3 liters of solution?





187- What is the total number of moles of H2SO4 needed to prepare 5.0

liters of a 2.0 M solution of H2SO4?

a. 2.5 b. 5.0

c. 10 d. 20

188- What is the molarity of a KF (aq) solution containing 116 grams of

KF in 1.00 liter of solution? (16)

a. 1.00 M b. 2.00 M

c. 3.00 M d. 4.00 M

189- What is the molarity of a solution that contains 0.202 mol KC1 in

7.98 L solution?

a. 0.0132 M c. 0.459 M

b. 0.0253 M d. 1.363 M

190- What is the molality of a solution that contains 5.10 mol KNO3 in

4.47 L water?

a. 0.315M b. 1.02M c. 0.779M d. 1.14M

191- What is the molarity of a solution that contains 125 g NaCl in 4.00L

solution?

a. 0.535M c. 8.56 M

b. 2.14 M d. 31.3 M

192- What is the molality of a solution that contains 31.0 g HC1 in 5.00L

water?

a. 0.062M c. 0.170M

b. 0.425M d. 15.5M

193- How many moles of HC1 are present in 0.70 L of a 0.33 M HCJ

solution?

a. 0.23 mol c. 0.38 mol

b. 0.28 mol d. 0.47 mol



194- An NaOH solution contains 1.90 mol of NaOH, and its

concentration is 0.555 M. What is its volume?

a. 0.623 L c. 1.05Lb. 0.911 L d. 3.42 L

195- How many milliliters water are needed to make a 0.171 M solution

that contains 1.00 g of NaCl?

a. 100 mL c. 171 mL

b. l000mL d. 17.1mL

196- What is the molarity of an HCI solution if 50.0 mL is neutralized in

a titration by 40.0 mL of 0.400 M NaOH?

a. 0.200 M c. 0.320 M

b. 0.280 M d. 0.500 M

197- What is the molarity of an HCI solution if 125 mL is neutralized in a

titration by 76.0 mL of 1.22 M KOH?

a. 0.371 M c. 0.617 M

b. 0.455 M d. 0.742 M

198- What is the molanty of an NaOH solution if 4.37 mL is titrated by

11.1mL of 0.0904 MHNO3?

a. 0.230 M c. 0.460 M

b. 0.355 M d. 0.620 M

199- What is the molarity of an H2SO4 solution if 49.0 mL is completely

titrated by 68.4 mL of an NaOH solution whose concentration is

0.333 M?

a. 0.116 M c. 0.465 M

b. 0.232 M d. 0.880 M

200- Calculate the molarity of a Ba(OH)2 solution if 1900 mL is

completely titrated by 261 mL of 0.505 M HNO3.

a. 0.0173 M c. 0.0322 M

b. 0.0254 M d. 0.0347 M



201- If 72.1 mL of 0.543 M H2SO4 completely titrates 39.0 mL of KOH

solution, what is the molarity of the KOH solution?

a. 0.317 M c. 100M

b. 0.502 M d. 2.01 M

202- If 114 mL of 0.008 04 M NaOH completely titrates 118 mL of

H3PO4 solution, what is the molarity of the H3PO4 solution?

a. 0.002 59 M c. 0.007 77 M

b. 0.005 18 M d. 0.0105 M

203- What is the molarity of a Ba(OH)2 solution if 93.9 mL is

completely titrated by 15.3 mL of 0.247 M H2SO4?

a. 0.0101 M c. 0.0402 M

b. 0.0201 M d. 0.0805 M

204- What is the molarity of an H3PO4 solution if 358 mL is completely

titrated by 876 mL of 0.0102 M Ba(OH)2 solution?

a. 0.0111 M b. 0.0166 M c. 0.0250 M d. 0.0333 M

205- A compound whose water solution conducts electricity and turns

phenolphthalein pink is

(1)HCI (3)NaOH

(2) HC2H3O2 (4) CH3OH

206- What is the molarity of a solution of NaOH if 2 liters of the solution

contains 4 moles of NaOH?

(1) 0.5M (3) 8M

(2) 2 M (4) 80 M

207- When excess hydroxide ions-were added to 1.0 liter of CaCI2

solution, Ca(OH)2 precipitate was formed. If all of the calcium ions

in the solution were precipitated in 7.4 grams of Ca(OH)2, then

what was the initial concentration of the CaCl2 solution?

(Ca = 40, H = 1, O = 16, Cl = 35.5)

a- 0.05 molar b- 0.10 molar c- 0.15 molar c- 0.20 molar



VI - Choose from column (B) what is suitable (A):

(A) (B)

1- One mole of a gas a- 12.04 x 1023 ions.

2- 64 g of oxygen gas b- 3 moles of the gas.

3- The molecular mass of nitrogengas equals

c-23.4g.

d- the density of the gas at STP x 22.4L.

4- 3 moles of nitrogen gas weigh f- 0.7 L.

5- 67.2L of carbon dioxide gas at(STP) is the volume1 occupiedby

g- occupies a volume of 44.8L at STP.

6- The number of moles of ionsproduced on dissolving 1 mole ofsodium nitrate (Na2CO3) in wateris

h- 20 L.

i- occupy a volume of 22.4L at STP.

j- 3 moles of ions.

7- The total number of ionsproduced on dissolving 1 mole ofpotassium nitrate (KNO3) inwater is

8- The mass .of sodium chloride(NaCI) needed to prepare itsaqueous solution, giver] that itsconcentration is 0.4 mole/Lequals (Na = 23, Cl = 35.5)

9- The volume of hydrochloric acid0.5 molar needed to neutralize0.5L of 0.7 molar sodiumhydroxide is

(a) (B) Acidic medium (C) Basic medium

1- Methyl orange a- Red I- Blue

2- Phenolphthalein b- yellow II- Colourless

3- Bromothymol blue c- blue III- Red

d- colourless IV- yellow



Choose from column (B) what is curable for column (A):

(A) (B)

1. Density a- equals 6.02 x 1023 particles.

2. Gay-lussac's law b- it is the molecular mass of a substance in

grams.

3. Avogadro's number c- states that "The volumes of the reacted and

produced gases exist in fixed ratios".

4. Avogadro's law d- it is a chemical process by which the

concentration of a solution can be determined by

using standard solution of known concentration.

5. Titration e- can be calculated by dividing the molar mass

of the substance by its molar volume.

6- Mole f- states that "Equal volumes of gases under the

same pressure and temperature contain equal

numbers of molecules".



VII – General Question:

(1) What is the scientific principle of each of the following;1. Volumetric analysis. 2. Gravimetric analysis3. Volatilization method 4. Precipitation method.

(1) What is the scientific contribution of each of the following:1. Gay - Lussac. 2. Avogadro.

(3) Mention the mathematical formulae relating between each two ofthe following quantities:1. The number of moles of a gas and its volume at (STP).2. The molecular mass of the gas and its density (g/L at STP).3. The concentration of the solution (mole/L) and both the number

of dissolved moles and the solution volume (L).4. The number of produced ions in the solution of a totally

ionizable substance and the number of its dissolved moles.5. The volumes and concentrations of each of the acid and the

alkali at the end point of their titration.(4) Chemical analysis provides" important Information for human life.

Mention the importance of chemical analysis in different fields.(5) Is the following statement true or false? (Explain your answer.)

"Equal volumes of different gases at STP do not have equalmases".

(6) What do we mean by=saying that:1. A 10% aqueous solution of calcium chloride.2. A 5% aqueous solution of glucose.3. A mixture contains 6.5 ppm of gold.4. Molar solution of sulphuric acid.5. A 0.5 molar solution of sodium hydroxide.

(7) Explain why sodium hydroxide solution not hydrochloric acidsolution can be used to differentiate between methyl orangeindicator and litmus indicator whereas hydrochloric acid solutionnot sodium hydroxide solution can be used to differentiate betweenbromothymol blue indicator and litmus indicator.



(8) Problems:1. How many particles (atoms, molecules or ions) are present in

each of the following:

a- 1 mole of copper (Cu) atoms. b- 0.5 mole of phosphate (PO4)3- ions.

c- 2 moles of CO2 molecules.

2. Determine the number of moles in each of the following:

a- 1 .80 x 1 024 atoms 0f lead.

b- 1.20 x 1025 ions of sulphate.

c- 3.9 x 1023 molecules of CH4.

3. How many moles of oxygen atoms are present in 5.00 moles

phosphorus pentoxide (P2O5)?

4. From the following equation:

CaCO3 CaO + CO2

i- How many molecules of calcium oxide are produced

from

heating 0.1 mole of calcium carbonate?

ii - How many moles of calcium carbonate are required to

produce 0.7 mole of carbon dioxide?

5. Carbon disulphide is an important industrial solvent. It is prepared

by the reaction of coke with sulphur dioxide.

5C(s) + 2SO2(g) CS2)I) + 4CO(g)

a- How many moles of carbon are needed to react with 5.44

moles SO2?

b- How many moles of carbon monoxide are formed at the same

time when 0.246 mole CS2 forms.

6. Methanol is made by reacting carbon monoxide and hydrogen at high

temperature and pressure. (C = 12, O = 16, H = 1)

CO(g) + 2H2(g) CH3OH(g)



a- How many moles of carbon monoxide are needed to produce

3.60x102g CH3OH?

b- Calculate the number of grams of hydrogen needed to produce

4.00 moles CH3OH.

c- How many grams of hydrogen are necessary to react with 2.85

moles CO?

7. A pure sample of KCIO3 contains 71 grams of chlorine atoms.

a- What is the mass of the sample?

b- Determine the number of moles of chlorine atoms present in 36.5 g

of KCIO3. (K = 39, Cl = 35.5, O = 16)

8. How many moles of KOH are needed to neutralize 196g of sulphuric

acid? (S = 32, O = 16, H = 1)

9. How many grams of sodium atoms are present in 23g of sodium

carbonate? (C = 12, Na = 23, O = 16)

10. Acetylene gas (C2H2) is produced by adding water to calcium carbide

(CaC2)

CaC2(s) + 2H2O(I) C2H2(g) + Ca(OH)2(aq)

How many grams of acetylene are produced by adding water to 5.00g

CaC2?

11. A sufficient amount of hydrogen is ignited with 4g of oxygen. Hew

many grams of water can be formed?

2H2 + O2 2H2O (H = 1, O =16)

12. An. impure sample of Hg(NO3)2, weighing 64.5g was dissolved in

water. The dissolved Hg(NO3)2 but not the impurities, then reacted

with excess Mg metal.

Hg(NO3)2 + Mg Mg(NO3)2 + Hg

What was the mass percent of Hg(NO3)2 in the sample if 23.6 g of

Hg were produced? (Hg = 200.6, N = 14, O = 16)



13. What is the mass of one carbon atom? (C = 12)

14. What volume will the following gases occupy at STP:

a- 0.554 mole of oxygen. b- 1 mole of hydrogen.

c- 2.5 moles of nitrogen.

15. Determine the number of moles of the following gases at STP:

a- 6.72 L of ammonia gas. b- 26.88 L of methane gas.

16. Consider this equation: CS2(I) + 3O2(g) CO2(g) + 2SO2(g)

a- How, many moles of carbon disulphide are needed to produce

16.6L of sulphur dioxide at STP?

b- Calculate the volurne of sulphur dioxide produced at STP when

27.9mL O2 react with carbon disulphide.

c- How many milliliters of carbon dioxide are produced at STP when

0.38L SO2 is formed?

17. In the following reaction, how many liters of SO2 at STP will result

from the complete burning of pure sulphur in 8L oxygen?

S(s) + O2(g) SO2(g)

18. What volume, in liters of NH3(g) is produced when 22.4L of N2(g) are

made to combine completely with a sufficient quantity of H2(g) under

appropriate conditions?

19. Under STP conditions, what is the mass of the following gases:

a- 22.4L of PH3 b- 33.6L of chlorine gas

(H = 1, CI = 35.5, P = 31)

20. What is the volume at STP occupied by:

a-48g of O3 b- 120 g of SO3 (O = 16, S = 32)

21. Which occupies more volume at STP:

a- 24.5 grams of N2 or 24.5 grams of NH3.

b- 10.0 grams of SO2 or 2Q.O grams of NO2.

(N=14, H = 1, O = 16, S = 32)



22. What mass of aluminum will be completely oxidized by 44.8L of

oxygen at STP? (Al = 27)

4Al + 3O2 2Al2O3

23. How many liters of O2(g) at STP can be released from thermal

dissociation of 50.3 grams of sodium chlorate (NaCIO3) into sodium

chloride and oxygen?

2 NaCIO3 2NaCI + 3O2 (Na = 23, Cl = 35.5, O=16)

24. Lithium nitride reacts with water to form ammonia and aqueous

lithium hydroxide.

a- What mass of water is needed to react with 32.9g Li3N?

b- When the above reaction takes place, how many molecules of NH3

are produced?

c- Calculate the number of grams of Li3N that must be added to an

excess of water to produce 15.0L NH3 (at STP). (N = 14, Li=7)

25. Ammonium nitrate with decompose explosively at high temperatures

to form nitrogen, oxygen, and water vapor.

2NH4NO3(s) 2N2(g) + 4H2O(g) + O2(g)

What is the total number of liters of gas formed when 228g NH4NO3

is decomposed? (assume STP) (O = 16, N = 14, H = 1)

26. What is the volume at STP occupied by:

a- 6.02 x 1023 molecules of NO.

b- 1.806 x 1023 molecules of NH3.

27. Determine the number of molecules of the following gases at STP:

a- 15.68 L of carbon dioxide gas.

b- 2240 mL of nitrogen dioxide gas.

28. Arrange the following gases ascendingly according to their volume at

STP, 0.5 mole oxygen, 25 g carbon dioxide, 15.05 x 1023 molecules

of hydrogen. (C = 12, O = 16)



29. A sample of water was electrolyzed to produce hydrogen and oxygen

gas, as shown in the reaction below: 2H2O(I) 2H2(g) + O2(g)

a- If 33.6 liters of gas were produced at STP, how many grams of

water were consumed in the reaction?

b- How many molecules of hydrogen are produced when 11.9L of

oxygen is formed at STP?

30. Calculate the density at STP conditions, in grams per liters, of each of

the following gases:

a- CO2 b- NH3 c- Cl2

(C = 12, O = 16, N = 14, Cl = 35.5, H = 1)

31. Calculate the molar masses for gases of the following densities at

STP:

a- 1.161 g/L b- 1.70 g/L c- 1.25 g/L

32. Calculate the density of a gas at STP, given that 0.5 mole of the gas

weighs 8g.

33. Determine the concentration of 0.7 mole of sodium hydroxide in 700

milliliters of water.

34. How many moles in 300 milliliters of a 0.7 molar sodium chloride

solution?

35. Two moles of potassium hydroxide were dissolved in water to form

5M solution. What is the volume of the solution?

36. How many moles of lead chromate, PbCrO4, can be produced by

addition of excess sodium chromate, Na2CrO4, to 25 mL of a 0.493M

solution of lead (II) nitrate, Pb(NO3)2?

(Pb = 207, Cr = 52, O = 16, Na = 23)

Pb(NO3)2 + Na2 CrO4 2NaNO3 + PbCrO4

37. Calcium carbonate dissolves in acidic solutions as shown in the

equation below:



CaCO3(aq.) + 2HNO3(aq.) Ca(NO3)2(aq.) + H2O(I) + CO2(g)

If excess of CaCO3 is added to 0.250 liters of a 2.00 molar HNO3

solution, what is the maximum volume of CO2 gas that could be

produced at standard temperature and pressure?

38. A quantity of sodium peroxide (Na2O2) is added to water and the

following reaction occurs.

2Na2O2(s) + 2H2O(I) 4NaOH(aq.) + O2(g)

If 70 mL of oxygen gas (at STP) and 150 mL of sodium hydroxide

solution are produced, then what is the molarity of the sodium

hydroxide solution?

(Na = 23, O = 16, H = 1)

39. A quantity of lithium nitride (Li3N) is added to water and the

following reaction occurs.

Li3N(s) + 3H2O(I) 3 LiOH(aq.) + NH3

If 100 mL of ammonia gas (at STP) and 255 mL of lithium hydroxide

solution are produced, then what is the molarity of the lithium

hydroxide solution?

(Na = 23, O = 16, H = 1)

40. Calculate the number of grams of nitric acid needed to prepare

350mL of a 6.00M nitric acid solution. (N = 14, H = 1, O = 16)

41. Calculate the molarity of ascorbic acid, C6H8O6 (vitamin C), solution

prepared by dissolving 1.80 g in enough amount of water to prepare

125 mL of solution.

(C = 12, H = 1, O = 16)

42. What volume, in mL, of a 0.48 M solution is required to provide 9.1g

of MgCl2?

(Mg = 24, Cl = 35.5)



43. What mass of the active metal magnesium is required to react exactly

with the hydrochloric acid in a 125.0 mL samples of a 0.211 M

solution of HCl?

Mg(s) + 2HCl(aq.) MgCl2(aq.) + H2(g) (Mg = 24)

44. How many hydrogen ions (H+) are found in one mole of HCl acid?

And what is the mass of these ions? (H = 1)

45. How many moles of H+ ions are there in 1L of a 5M solution of HCl?

46. If 52 grams of Ba(NO3)2 (molar mass 260 grams) are completely

dissolved in 500 milliliters of distilled water, then what are the

concentrations of the barium and nitrate ions?

47. What is the molar concentration of all ions in a 0.02 M aqueous

solution of lead nitrate Pb(NO3)2?

48. How many grams of NaOH are needed to make 100g of a 5%

solution of NaOH?

49. How many grams of H2SO4 are in 1000 gm of a 10% solution?

50. What is the mass percent of oxygen in one mole of Ca(NO3)2?

(Ca = 40, N = 14, O = 16)

51. A copper are contains 13.22% by mass CuCO3. How many tons of

the ore are required to produce 227.27 Kg of Cu metal?

(Cu = 63.5, C = 12, O = 16)

2 CuCO3 2CU + 2CO2 + O2

52. Silver metal can be recovered from an ore containing silver carbonate

(Ag2CO3) by decomposition reaction

2 Ag2CO3 4Ag + 2CO2 + O2

53. What mass of silver ore, in tons, is needed to produce 226.8 Kg of

silver if the ore is 24.21% by mass silver carbonate? Assume

complete decomposition of the silver carbonate.

(Ag = 108, C = 12, O = 16)



54. Adipic acid, H2C6H8O4 [HOOC. (CH2)4. COOH], is raw material

used for the production of nylo. It is made commercially by oxidation

of cyclohexane, C6H12.

2C6H12 + 5O2 2H2C6H8O4 + 2H2O

a- In one of these reactions, 25.0g of cyclohexane were

completely consumed. What is the expected (theoretical)

mass of adipic acid?

b- If the actual mass of adipic acid in the previous reaction is

33.5g, what is the percent yield of adipic acid?

(C = 12, H = 1, O = 16)

55. When HgO is heated, it decomposes into mercury and O2. If 62.7 g of

mercury is actually obtained from the decomposition of 75.8 g of the

oxide, what is the percent yield of mercury? (Hg = 200.6, O = 16)

56. Copper metal is extracted from copper (I) sulphide ore (Cu2S):

First, by roasting it in a limited amount of atmospheric oxygen gas in

order to get rid partially of sulphur dioxide and copper (II) oxide is

obtained.

Cu2S + 2O2 2CuO + SO2

Then, the produced copper (II) oxide is reduced by the remaining

copper (I) sulphide ore.

2CuO + Cu2S 4Cu + SO2

Calculate the mass of copper (I) sulphide ore, which contains 50%

impurities, needed to produce 3 tons of copper metal.

(Cu = 63.5, S = 32)

57. Fish generally need an oxygen concentration in water of at least 5

ppm for survival. Will river water that contains 7 mg of oxygen per

liter contain sufficient oxygen to sustain fish life? (1L of water

weighs 1 Kg).



58. A carbon dioxide concentration in water of 200 ppm or higher is

lethal (ممیت) to fish. Will river water that contains 0.62 g of dissolved

carbon dioxide per 2 Kg be toxic to fish?

59. A 3Kg of a mixture containing 0.6g of sodium carbonate. Calculate

the concentration of sodium carbonate in ppm.

60. IN the laboratory, 20.0 mL of an aqueous solution of calcium

hydroxide, Ca(OH)2, was used in a titration. A drop of

phenolphthalein was added to it to indicate the end point. The

solution turned colourless after 20.0 mL of standard solution of

0.050M HCl solution was added.

What was the molarity of the Ca(OH)2?

61. What volume, in liter, of 0.0385M HCl is required to react with

22.0mL of 0.130M NaOH?

62. How many milliliters of 0.3M Ba(OH)2 solution are required to

neutralize 45mL of 0.51M H2SO4 solution?

63. Find out the mass of sodium hydroxide that presents in 25mL

solution which consumes, by titration, 15mL of 0.1M of hydrochloric

acid solution.

(Na = 23, O = 16, H = 1)

64. A 15.3ml of potassium hydroxide was titrated with 22.3ml of 0.025m

sulphuric acid.

a- What was the molarity of potassium hydroxide?

b- What was the mass of potassium hydroxide?

(K = 39, O = 16, H=1)

65. A 0.43g calcium hydroxide dissolved in its solution was neutralized

with 118mL of sulphuric acid. What was the molarity of sulphuric

acid? (Ca = 40, O = 16, H = 1)



66. A 1.25g sample of impure Na2CO3 is found to react completely in the

70 mL of 0.125M HCI. The equation for the reaction is:

Na2CO3)s) + 2HCI(aq) 2NaCI(aq) + CO2(g) + H2O(L)

What was the mass percent of sodium carbonate in the impure

sample?

(Na = 23, C = 12, O = 16, H = 1, Cl = 35.5)

67. A 0.53g of a mixture of solid substance containing sodium hydroxide

and sodium chloride was titrated with 0.25M hydrochloric acid. The

complete reaction takes place by consumption of 15mL of the acid.

Calculate the percentage of sodium hydroxide in the mixture.

(Na = 23, O = 16, H = 1)

68. A 1.7g of a mixture of solid substance containing potassium

hhydroxide and potassium sulphate was titrated with 0.06M sulphuric

acid. The complete reaction takes place by consumption of 138mL of

the acid. Calculate the percentage of potassium sulphate in the

mixture. (K = 39, O = 16, H = 1)

69. A 1.023 grams of hydrated cobalt (II) sulphate (CoSO4 – XH2O) was

strongly heated until a constant mass 0.603 grams. Calculate the

percentage of water of crystallization of the hydrated cobalt (II)

sulphate, then calculate the number of water molecules of

crystallization and write the molecular formula of the hydrated salt.

(Co = 59, S = 32, O = 16, H = 1)

70. Find the percentage of water of crystallization and the molecular

formula of the hydrated iron (II) chloride crystals (FeCl2 – XH2O)

from the following givens:

Mass of hydrated sample of iron (II) chloride = 3.768 grams.

Mass of anhydrous sample of iron (II) chloride = 2.405 grams.

(Fe = 56, Cl = 35.5, H = 1, O = 16)



71. A 1.687 grams of hydrated magnesium sulphate salt (MgSO4 –

XH2O) was strongly heated until a constant mass of 0.824 grams.

a- Calculate the percentage of water of crystallization of the hydrated

magnesium sulphate.

b- Find out the number of water molecules of crystallization and

write the molecular formula of the salt.

(Mg = 24, S = 32, O = 16, H = 1)

72. Find the molecular formula of washing soda crystals (hydrated

sodium carbonate) given that, the mass of the hydrated crystals before

heating is 5 grams and after strong heating and constant mass is 1.853

grams. (Na = 23, C = 12, O = 16, H = 1)

73. Magnesium, calcium and zinc all react in the hydrochloric acid as

follows (where M represents any of these metals)

M(s) + 2HCI(aq) MCI2 + H2(g)

A sample of one of these metals reacts completely with the acid in

27.9 mL of 2.48M HCI, and the resulting solution is evaporated to

dryness. The residue MCI2 has a mass of 4.72g. What is identity of

the metal used?

(Cl = 35.5, Mg = 24, Ca = 40, Zn = 65.5)

74. Iron, nickel and tin all react in the hydrochloric acid as follows

(where M represents any of these metals)

M(s) + 2HCI(aq) MCI2 + H2(g)

A sample of one of these metals reacts completely with the acid in

34.2mL of 4M HCI, and the resulting solution is evaporated to

dryness. The residue MCI2 has a mass of 8.87g. What is the identity

of the metal used?

(Cl = 35.5, Fe = 56, Ni = 58.7, Sn = 118.7)



75. Calculate the mass of copper sulphate required to precipitate 5 grams

of copper hydroxide according to the following equation:

CuSO4 + 2NaOH Cu(OH)2 + Na2SO4

(Cu = 63.5, S = 32, O = 16, H = 1)

76. Sodium hydroxide solution was added to iron (II) sulphate solution,

the precipitate, iron (II) hydroxide was separated by filtration then

drying, its mass was 2.3 grams. Calculate the mass of iron (II)

sulphate in its solution.

(Fe = 56, S = 32, O = 16, H = 1)

77. Calculate the number of moles of silver chloride (AgCl) precipitated

from the reaction of 5.85g sodium chloride (NaCl) with 17 grams of

silver nitrate (AgNO3).

(Ag = 108, Na = 23, Cl = 35.5)

78. HCl(aq) + AgNO3(aq) AgCI(s) + HNO3(aq)

One half liter of a 0.20 molar HCI solution is mixed with a sufficient

amount of AgNO3 solution.

A reaction occurs forming a precipitate as shown above.

If the reaction goes to completion, then what is the mass of AgCI

produced?

(Ag = 108, N = 14, O = 16, CI = 35.5, H = 1)

79. How many milliliters of barium chloride solution (containing 30g of

BaCI2 – 2H2O in one liter) is needed to precipitate the sulphate ions

from a solution containing 0.5 grams of potassium sulphate?

BaCL2 – 2H2O + K2SO4 2KCI + 2H2O + BaSO

(Cl = 35.5, Ba = 137, S = 32, K = 39, O = 16, H = 1)

A three gram portion of impure barium chloride was dissolved in

water. Excess of sodium sulphate solution was added to precipitate 2

grams of barium sulphate. Calculate the % of barium in the sample.



80. The equation for the complete combustion of ethane (C2H4) is:

C2H4(g) + 3O2(g) 2CO2(g) + 2H2O(g)

If 2.70 moles C2H4 are reacted with sufficient amount of oxygen, then

calculate the number of moles of water produced.

81. What is the weight of one mole of Ca(OH)2? (Ca=40, H=1, O=16)

82. A student examined 2.0 moles of an unknown carbon compound and

found that the compound contained 48 grams of carbon, 64 grams of

oxygen, and 8 grams of hydrogen, which of the following could be

the molecular formula of the compound? (C=12, O=16, H=1)

a- CH2O b- CH2OH c- CH3COOH d- CH3CO

83. Determine the number of moles in each of the following:

a- 275 g boron. (B = 11, S = 32, Na = 23, O = 16, Ca = 40)

b- 200 g sodium sulphate.

c- 120 tones of calcium.

84. What is the weight of each of the following:

a- 0.100 mole sulphur. b- 1.25 mole glucose (C6H12O6).

c- 6.02 x 1023 molecules I2. d- 2.5 x 1020 atoms of magnesium.

(S = 32, C = 12, H = 1, O = 16, I = 127, Mg = 24)

85. How many molecules in each of the following:

a- 119 g KBr. b- 20 g NaCI.

(K = 39, Br = 80, Na = 23, CI = 35.5)

86. Arrange the following in order of mass from the smallest mass to the

largest:

1.0 mole Ar, 3.0 x 1024 atoms Ne, 20g Kr. (Kr=84, Ar=40, Ne=20)

87. Which of the following contains the largest mass of nitrogen atoms?

(N = 14, O = 16).

a- 0.40 mole N2O5. b- 0.60 mole NO.

c- 0.15 mole N2O. d- 0.50 mole NO2.



2- Calculate the mass of each of the following:

(1) One mole of water.(2) 0.1 mole of sulphuric acid.

The atomic massesof the used elements

(3) 3 moles of acetylene. OHCaSNaCFeNLiAlMg

===========

1614032231255.81472724

(4) 0.5 mole of red iron oxide (haemaite).(5) 2.61 moles of carbon monoxide.(6) Lithium in 1 gm of lithium carbonate.(7) Oxygen in 0.1 gm of adrenaline

hormone (C9H13NO3)(8) 3 x 1020 atoms of sodium.

3- Calculate the number of moles in each of

the following:

(1) 540 gm of glucose C6H12O6

(2) 74 gm of calcium hydroxide.

(3) 5.4 gm of aluminum.

(4) 12 gm of magnesium.

(5) 36 gm of water.

4- Calculate the number of molecules in each of the following (at S.T.P):

(1) 0.2 mole of carbon dioxide.

(2) 16 gm of sulphur dioxide.

(3) 5.23 gm of glucose C6H12O6

(4) 0.1 mole of perchloric acid.

(5) 9.8 gm of orthophosphoric acid.



5- Calculate the number of atoms in each of the following (at S.T.P.):

(1) The carbon in one mole of glucose (C6H12O6)(2) Copper found in a sample whose mass is 3 gm.


(3) The carbon found in 33.4 gm of isopropylalcohol C3H7OH

COHSPClCuKNaNBi

===========

12161323135.563.5392314209

(4) The carbon found in 32 gm of methane gas.(5) Potassium found in 1.03 gm of potassium

superoxide.(6) Oxygen found in 7.8 gm of sodium peroxide.

6- Calculate the volume occupied by each

of the following gases (at S.T.P.):

(1) one mole of ammonia gas.

(2) 54 gm of water vapour.

(3) Five moles of nitrogen gas.

(4) 300 gm of nitric oxide gas.

(5) 0.1 mole of methane gas.

(6) 3.4 gm of hydrogen sulphide gas.

7- Calculate the density of each of the following:

(1) Hydrogen gas. (2) Methane gas.

(3) Ethylene gas. (4) Acetylene gas.

(5) Nitrogen gas. (6) Phosphorus vapour.

(7) Bismuth vapours. (8) Chlorine gas.

8- Calculate the molar concentration (mole/litre) for each of the

following:

(1) A solution of one litre that contains 106 gm of sodium carbonate.

(2) A solution of two litres that contains 160 gm of sulphur trioxide.



(3) A solution of one litre that contains 117 gm of table salt.

(4) A solution of 300 ml that contains 0.5 mole of silver nitrate.

(5) A solution of 250 ml that contains 40 gm ofcaustic soda.


(6) A solution of 200 ml that contains 0.098 gm of NaAgCNSClMgOH

=========

2310812143235.524161

sulphuric acid.

9- Calculate themass used to prepare 100 ml from twomolar solution of the following compounds:

(1) Magnesium sulphate MgSO4

(2) Anhydrous magnesium chloride MgCl2

(3) Hydrated magnesium chloride MgCl2.6H2O

(4) Ammonium hydroxide NH4OH

(5) Sodium chlorate NaClO3



(3) Miscellaneous problems:

The Mole

(1) Calculate the mass of nitrogen produced from the oxidation of 20 of

gm hydrazine in (N2H4). According to the equations:

N2H4 + O2 N2 + 2H2O (N = 14, H=1)

(2) Calculate the mass of oxygen required to produce 3.5 gm of carbon

dioxide gas according to the equation:

CH4 + 2O2 CO2 + 2H2O (C =12, O =16)

(3) From the reaction: SiO2 + 3C SiC + 2CO

Calculate the mass of SiC produced from the reaction of 15 gm of

carbon with excess of SiO2 (C=12, Si=28)

(4) Calculate the mass of water consumed by plant during the

photosynthesis process to react with 20 gm of carbon dioxide gas

according to the equation:

6CO2(g) + 6H2O(L) C6H12O6(s) (H= 1, O =16, C =12)

(5) Calculate the number of oxygen moles required for combustion of

68 gm of ammonia according to the equation:

4NH3(g) + 5O2(g) 4NO(g) + 6H2O(L) (N=14, H=1)

(6) Calculate the mass of nitric oxide produced from burning of 68 gm

of ammonia gas according to the equation:

4NH3(g) + 5O2(g) 4NO(g) + 6H2O(L) (N=14, H=1, O=16)

(7) From the reaction:

CuO(s) + H2SO4(aq) CuSO4(aq) + H2O(L)

(a) What is the mass of copper sulphate that can be obtained from

the reaction of 10 gm of copper II oxide with excess of sulphuric

acid?

(b) What is the mass of sulphuric acid that reacts with 15 gm of

copper oxide? (Cu=63.5, O=16, H=1, S=32)




Al4C3(s) + 12HCI(aq) 4AlCl3(aq) + 3CH4(g)

If the mass of evolving methane gas is 1.257 gm calculate the mass

of:

(a) Al4C3 used (b) AlCl3 formed (Al=27, C=12, Cl=35.5)

(9) Calculate the mass of sodium required to produce 29.25 gm of

sodium chloride. (Na=23, Cl=35.5)

(10) Calculate the mass of calcium oxide produced from the thermal

decomposition of one mole of calcium carbonate.

(Ca=40, O=16, C=12).

(11) Glucose C6H12O6 found in food burns according to the following

equation:

C6H12O6(g) + 6O2(g) 6CO2(g) + 6H2O(L) (C=12, H=1, O=16)

(12) Calculate the mass of water produced from:

(a) the combustion of 2 moles of glucose.

(b) eating a piece of sweet that contains 14.2 gm of glucose.


Mg2Si(s) + 4H2O(L) 2Mg(OH)2(g) + SiH4(g)

Calculate:

(a) The number of SiH4 moles formed in the reaction of 2.95 gm of

Mg2Si with water.

(b) The mass of water required to react with 2.95 gm of Mg2Si

(Mg = 24, Si = 28, H = 1, O = 16)

(14) A sample of galena alloy contains 10% of lead II sulphide PbS used

to produce lead. If the rate of consumption at a certain factory is 200

tons of the alloy per a day:

(a) Calculate the mass of lead II sulphide consumed per a day?

(b) Calculate the mass of lead produced per a day? (Pb=207, S=32)



(15) A coin of a mass 4.5 gm made of copper and nickel alloy (75% of

copper, 25% of nickel).

(a) Calculate the mass of the copper required to produce 100

thousand coins.

(b) If the copper is produced from CuO ore, Calculate the mass of

the ore required 100 thousand coins? (Cu = 63.5, O = 16)

(16) A, B, C, and D are four elements

whose atomic masses are 8, 10, 15

Compound Bound

elements

The weight

percentage

& 22 respectively when they are

combined together according to the

weight ratios as in the table, four

compounds are produced:

(1)

(2)

(3)

(4)

A + B

A + C

D + C

D + B

4 : 5

16 : 15

4.4 : 4.5

11 : 15

(a) What are the chemical formula of

the found compounds formed?

(b) What is the valency of each of the four elements A, B, C & D?

The relation between moles and the numbers of molecules, atoms or

ions:

(17) Calculate the number of water molecules found in 3.14 moles of it.

(18) Calculate the number of moles oxygen atom found in a sample of

vitamin (C) which contains 2.58 x 1024 oxygen atoms?

(19) Calculate the number of vitamin (C) molecules, whose chemical

formula is (C6H8O6), found in a tablet of pure vitamin (C) whose

mass is 0.25 gm. (C=12, H=1, O=16)

(20) Calculate the number of water vapour molecules produced from the

reaction of 0.1 gm of hydrogen with excess of oxygen gas.

(H = 1, O = 16)



(21) Calculate the mass of sodium that contains a number of sodium

atoms equals to the number of aluminium atoms in 300 Kg of

aluminium. (Al = 27, Na = 23)

(22) Calculate the number of chloride ions produced from dissolving 39

gm of sodium chloride in water. (Na = 23, Cl = 35.5)

(23) Calculate the number of both sodium and sulphate ions produced

from dissolving of 7.1 gm of sodium sulphate in water according to

the equation: Na2SO4(s) + H2O(L) 2Na+(aq) + SO4

-2(aq)

(Na = 23, S = 32, O = 16)

(24) Calculate the number of iodide ions required to react with 3.5x10-5

moles of ozone gas according to the equation:

O3)g) + 2I-(aq) + H2O(L) O2(g) + I2(aq) + 2OH-

(aq)

(25) Calculate the number of Ag2 CrO4 molecules formed from 0.4

moles of silver ions Ag+ according to the equation:

2Ag+(aq) + CrO4

2-(aq) Ag2CrO4(s)

(26) The following equations show the steps to produce sulphuric acid

in industry.

(a) S + O SO2

(b) SO2 + ½ O2 SO3

(c) SO3 + H2SO4 H2S2O7

(d) H2S2O7 + H2O 2H2SO4

(1) Which of the previous steps shows the reaction between gases?

(2) Calculate the mass of sulphuric acid that could be produced it

we started the reaction by a ton of sulphur.

(H = 1, S = 32, O = 16)

(27) The urine of healthy person contains 2.23% by mass urea

(NH2)2CO. If the rate of extracting urine is 1.5 kg per a day,

calculate the mass of nitrogen in the urea in human urine all over

the year (365 days). (N=14, H=1, C=12, O=16)



The relation between the mole and the volume of gas:

(28) Calculate the volume of ammonia gas produced from the

combination of 11.2 liters of nitrogen gas with excess of hydrogen

gas (at S.T.P).

(29) Calculate the mass of potassium chlorate KCIO3 required to obtain

one litre of oxygen gas (at S.T.P). According to the equation:

2KCIO3(s) 2KCI(s) + 3O2(g) (K=39, Cl=35.5, O=16)

(30) What is the volume of oxygen gas evolved from heating 49 gm of

potassium chlorate KCIO3 (at S.T.P) according to the equation:

2KCIO3(s) 2KCI(s) + 3O2g (K=39, Cl=35.5, O=16)

(31) Urea CO(NH2)2 is produced from the reaction of carbon dioxide

gas with ammonia gas according to the reaction:

CO2(g) + 2NH3(g) CO(NH2)2(g) + H2O(v)

Calculate the volume of carbon dioxide gas and ammonia gas (at

S.T.P) required to produce 2.5 Kg of urea.

(C=12, O=16, H=1, N=14)

(32) Hydrochloric acid reacts with manganese dioxide according to the

following reaction:

MnO2(s) + 4HCl(aq) MnCl2(s) + 2H2O(L) + Cl2(g)

Calculate:

(a) the volume of chlorine gas produced form the reaction of 45gm

of manganese dioxide with a sufficient amount of acid (at S.T.P)

(b) the mass of acid required to produce 44.8 litres of chlorine gas

(at S.T.P) (Mn=55, O=16, H=1, Cl=35.5)

(33) If the mass of one litre of a gas at 273 K and pressure 760 ml/Hg

equals 5.236 gm, calculate the mass of one mole of that gas.

(34) How many litres of oxygen required to burn 25 gm of carbon

completely? (C = 12)



(35) What is the mass of sulphur required to be burnt in air to produce

4.48 litres of sulphur dioxide (at S.T.P). (S=32, O=16)

(36) Calculate the volume of the gas produced from the reaction of a

piece of potassium whose mass is 13 gm with water.

(K=39, H=1)

(37) Calculate the volume of carbon dioxide gas evolved (at S.T.P)

when a piece of chalk CaCO3 whose mass is 50 gm dissolves in a

sufficient amount of hydrochloric acid. (Ca=40, C=12, O=16)

(38) Claculate the mass of sodium chloride and the volume of carbon

dioxide (at S.T.P) produced from the reaction of hydrochloric acid

with 53 gm of sodium carbonate. (Na=23, C=12, O=16, Cl=35.5)

(39) Calculate the volume of oxygen (at S.T.P) required to burn 100

cm3 of methane gas completely according to the equation:

Ch4(g) + 2O2(g) CO2(g) + H2O(L)

(40) The opposite figure shows a model

of a with 25.2 gm orange

ammonium dichromate crystals

(NH4)2 Cr2O7 inside it, and when

a lighted match was thrown in the

model, the crystals burn forming

clouds of green chromium III oxide

dust, in addition to the evolving

of water vapour and nitrogen gas according to the following

equation:

(NH4)2 Cr2O7(s) Cr2O3(s) + 4H2O(v) + N2(g)

Calculate:

(a) The number of ammonium dichromate moles used in the

volcano model.



(b) The number of moles of chromium III oxide formed.

(c) The mass of water vapour produced.

(d) The volume of nitrogen gas evolving (at S.T.P)

(N=14, H=1, Cr=52, O=16)

(41) Calculate the volume of oxygen gas required to produce 200 ml of

nitric oxide gas. (at S.T.P).

The relation between the mole and the density of gas:

(42) Calculate the density of oxygen gas (at S.T.P).

(O=16) (1st session 06)

(43) Calculate the density of hydrazine gas N2H4 (at S.T.P).

(N=14, H=1)

(44) Calculate the molecular mass of a gas whose density is 1.25

gm/litre.

(45) Calculate the mass of one mole of NO2 gas, knowing that its

density is 2.05 gm/litre.

(46) If the absolute density of hydrogen gas is 0.0893 gm/litre, calculate

the volume of 1 mole of it (at S.T.P). (H = 1)

(47) If the absolute density of carbon dioxide gas is 1.96 gm/litre,

calculate the volume of one mole (at S.T.P) (C=12, O=16).

The relation between the mole and concentration of solutions:

(48) Table sugar is the sucrose C12H22O11

Calculate:

(a) the mass of one mole of it.

(b) The number of moles of sucrose in a sample whose mass is 684

gm.

(c) The number of molecules in a sample whose mass is 5.7 gm.



(d) The concentration of the solution in which the 500 ml of it

contains 171 gm of sucrose. (C=12, H=1, O=16)

(49) Calculate the molar concentration of potassium chloride if 10 gm

of it is dissolved in water and the solution was complete up to 200

ml. (K=39, Cl=35.5)

(50) Calculate the volume of sulphuric acid solution that contains 3.92

gm of the acid and its concentration is 0.05 molar.

(H=1, S=32, O=16)

(51) Calculate the number of NaCl moles in 25 ml of sodium chloride

solution and its concentration is 1.85 mole/litre.

(52) Calculate the mass of nitric acid found in 200 ml of a solution and

its concentration is 3.2 molar. (H=1, N=14, O=16)

(53) Calculate the gram molecular mass of a certain substance when 14

gm of it are dissolved in water to form a solution whose volume is

1500 ml and its concentration is 0.25 moles/lire.

(54) Calculate the mass of sodium hydroxide required to prepare 350 ml

of its solution whose concentration is 1.25 mole/lire.

(Na=23, O=16, H=1)

(55) If 50 ml of phenol solution C6H6O contain I gm of it. Calculate the

molarity of that solution. (C=12, H=1, O=16)

(56) Calculate the concentration of sodium ions Na+ in a mixture that

contains 54 ml of potassium nitrate solutions with 114 ml sodium

nitrate solution whose concentration is 0.357 mole/litre.

(57) Calculate the concentration of hydroxide ions OH in a mixture

containing 200 ml of potassium hydroxide solution whose

concentration is 0.12 mole/litre with 300 ml of calcium hydroxide

solution whose concentration is 0.15 mole/litre.



Quantitative analysis by neutralization:

(1) Calculate the volume of hydrochloric acid 0.1 molar required to

neutralize with 20 ml of sodium carbonate solution 0.5 molar.

(2) Calculate the concentration of the phosphoric acid giving that each

80 ml of it, neutralizes with 60 ml of calcium hydroxide solution

0.4 molar.

(3) Calculate the concentration of 25 ml of sodium hydroxide solution

required to neutralize with 8 ml of sulphuric acid 0.1 molar.

(4) Calculate the volume of calcium hydroxide whose concentration is

0.02 mole/litre required to neutralize with 25 ml of hydrochloric

acid 0.05 molar.

(5) How many milliliters of sodium hydroxide 0.25 molar neutralizes

with 100 ml of sulphuric acid 0.4 molar? How many moles of

sulphuric acid dissolved in that solution? How many moles of

sodium hydroxide are required to react with that acid? And what is

the mass of sodium sulphate formed in the produced solution.

(Na=23, O=16, H=1, S=32)

(6) 75 ml of hydrochloric acid 0.1 molar is added to 125 ml of barium

hydroxide solution Ba(OH)2 and the solution stayed as alkaline as

it is, and to neutralize it, another 35 ml of hydrochloric acid should

be added. Calculate the concentration of barium hydroxide

solution.

(7) 14.2 gm of potassium chloride salt is dissolved in an amount of

water to form a litre of the solution and is required to react with 25

ml of that solution 33.2 ml of silver nitrate solution. Calculate the

concentration of silver nitrate solution. (K=39, Cl=35.5)

(8) Find the mass of sodium hydroxide dissolved in 25 ml which is

consumed on neutralize with 15 ml of hydrochloric acid 0.1 molar.



(Na=23, O=16, H=1)

(9) What is the mass of sodium hydroxide in its solution, neutralized

with 20 ml of sulphuric acid 0.22 molar?

(H=1, S=32, O=16, Na=23)

(10) What is the mass of hydrochloric acid required to neutralize with

22 ml of sodium carbonate solution 0.11 molar? (H=1, Cl=35.5)

(11) 0.1 gm of a mixture of sodium hydroxide and sodium chloride was

titrated with 10 ml of hydrochloric acid of 0.1 molar. Calculate the

percentage of sodium hydroxide in the mixture. (1st session 07)

(Na=23, H=1, O=16)

(12) One litre of sodium carbonate 0.3 molar is added to litre of

hydrochloric acid 0.4 molar. What is the excess substance?

Calculate the numer of moles of that substance.

Quantitative analysis by volatilization:

(13) A sample of hydrated barium chloride whose mass is 2.6903 gm is

strongly heated up to a constant mass of 2.2923 gm. Calculate the

percentage of crystallization water in the sample.

(14) A sample of sodium chloride is heated and the results were as the

following:

* The mass of the empty crucible = 9.0005 gm.

* The mass of the crucible with the sample = 9.4211 gm

* The mass of the crucible with the sample after drying = 9.4143 gm.

Calculate the percentage of humidity in that sample.

(15) If the mass of an empty crucible = 24.3238 gm.

And its mass with a sample of hydrated barium chloride = 27.041

and its mass after heating and stabilizing its mass = 26.6161 gm.

Calculate: (Ba=137, Cl=35.5, H=1, O=16)



(a) The number of molecules of crystallization were in a moleculeof hydrated barium chloride.

(b)The formula of hydrated barium chloride.(16) A sample of potassium chromium alum K2SO4.Cr2(SO4)3.XH2O is

heated and the results were:* The mass of the empty crucible = 10 gm.* The mass of the crucible with the sample = 29.96 gm.* The mass of the crucible after heating = 21.32 gm.

(a) What is the value of (X)?(b) Calculate the percentage of crystallization water in the

compound. (K=39, S=32, O=16, Cr=52, H=1)(17) 0.4122 gm of an organic compound is completely burnt, the

produced water vapour and carbon dioxide are 0.3618 gm, 0.762gm respectively.

(a) Calculate the percentage of carbon and hydrogen in thatcompound.

(b) Does that organic compound contain any other element? (Givereasons). (C=12, H=1, O=16)

Quantitative analysis by precipitation(18) On adding sodium sulphate solution to a solution of barium

chloride, 2gm of barium sulphate are separated. Calculate the massof barium chloride used. (Ba=137, Cl=35.5, S=32, O=16)

(19) The bromide ions in potassium bromide solution are precipitated inthe form of silver bromide whose mass is 0.251 gm. Calculate themass of potassium bromide in that solution.

(K=39, Bar=79.9, Ag=108)(20) Chloride ions in potassium chloride solution are precipitated in the

form of silver chloride whose mass is 0.1562 gm. What is the massof chloride ion in that solution? (Ag= 108, Cl=35.5)



(21) On dissolving 2 gm of an impure sample of sodium chloride inwater and excess of silver nitrate solution, 4.628 gm of silverchloride are precipitated. Calculate the percentage of chlorine inthe sample. (A= 108, Cl= 35.5) (1st session 06)

(22) 0.2176 gm of a barium ore is dissolved in nitric acid, and addingsulphuric acid, barium precipitates in the form of barium sulphateand when it is filtered and dried the mass of the precipitate was0.0214 gm. Calculate the percentage of barium in the sample.

(Ba = 137, S=32, O=16)(23) 0.411 gm of iron III oxide is formed when 0.5 gm of magnetite ore

is oxidized. Calculate the percentage of black oxide in the ore.(Fe = 55.8, O =16)

(24) Silver nitrate solution was added to 25 ml of hydrochloric acidsolution whose concentration is unknown. When the silver chlorideprecipitate was filtered and dried, its mass was 0.538 gm. Calculatethe molarity of hydrochloric acid knowing that all the chlorideprecipitated. (Ag = 108, Cl= 35.5, H=1)

(25) From the reaction:BaCl22H2O + H2SO4 BaSO4 + 2HCl + 2H2OCalculate:(a) The mass of barium chloride crystals that gives 0.5 gm of

barium sulphate precipitate.(b) The volume of sulphuric acid of concentration one molar that

reacts with 0.25 gm of hydrated barium chloride.(Ba = 137, Cl = 35.5, S = 32, O = 16)

(26) To obtain the iron in the blast furnace, carbon monoxide reducesiron (III) oxide and if the haematite ore contains 45% of iron (III)oxide.How many kilograms of haematite ore required to produce 1000kilograms (one ton) of iron? (Fe = 56, O = 16)



Chapter 6 Section (B) School Book Questions:

(1) Calculate the mass of 0.5 mole of water.

(2) Calculate the number of molecules in 0.2 mole of carbon dioxide.

(3) Calculate the number of molecules in 16 grams of sulphur dioxide.

(4) Calculate the mass of 3x1020 sodium atoms.

(5) Calculate the mass of sodium metal needed to produce 29.25 grams

of sodium chloride.

(6) Calculate the mass of calcium oxide produced by thermal

decomposition of 1 mole of calcium carbonate.

(7) Calculate the number of water vapor molecules produced by the

reaction of 0.1 gram of hydrogen with excess oxygen.

(8) Calculate the number of moles of oxygen needed for the

combustion of 68 grams of ammonia.

4NH3 + 5O2 4NO + 6H2O

(9) Calculate the mass of nitric oxide produced from the previous

reaction.

(10) The chemical formula of vitamin C is C6H8O6. Calculate the

number of molecules present in 0.25 gram tablet of the vitamin.

(11) The human body converts food glucose (C6H12O6) into carbon

dioxide and water according to the equation:

C6H12O6 + 6O2 6CO2 + 6H2O

If a person eats a piece of a sweet containing 14.2 grams of

glucose, then calculate the mass of water formed in the body.

(12) Silicon carbide is a substance used for the preparation of emery

papers and produced by the chemical reaction:

SiO2 + 3C SiC + 2CO



Calculate the mass of SiC which is produced from the reaction of

15 grams carbon.

(13) The photosynthesis reaction in plants is represented by the

equation:

6CO2 + 6H2O C6H12O6 + 6O2

Based on this equations, calculate the mass of water needed to

react with 20 grams of carbon dioxide.

(14) Carbon monoxide is one of air pollutants produced from fuel

combustion. Calculate the mass in grams present in 2.61 moles of

carbon monoxide.

(15) Lithium carbonate compound (Li2CO3) is used for the treatment of

depression. Calculate the mass of lithium metal present in 1 gram

of lithium carbonate.

(16) Adrenaline is a hormone excreted under tension in the blood, its

chemical formula is C9H13NO3. Calculate the mass of oxygen

present in 0.1 gram of adrenaline.

(17) Hydrazine (N2H4) is used as a fuel for some rockets. Calculate, the

mass of nitrogen gas produced from oxidation of 20 grams of

hydrazine:

N2H4 + O2 N2 + 2H2O

(18) Methane gas (CH4) is the main component of the natural gas. The

combustion of the gas proceeds according to the equation:

CH4 + 2O2 CO2 + 2H2O

Calculate the mass of oxygen needed to produce 3.5 grams of

carbon dioxide gas.

(19) An iron oxide ore contains 3C|% of iron oxide (Fe O ). How many

tons are required for production of one ton of iron metal?



(20) Find out the mass of chlorine gas produced by electrolysis of 200

grams of. sodium chloride solution.

(21) A 25 ml of sodium hydroxide solution was titrated with 0.1 molar

sulphuric acid solution. The acid volume consumed at the

equivalent point is. 8 ml. Calculate the concentration of sodium

hydroxide solution.

(22) Calculate the volume of 0.1 molar hydrochloric acid solution

required for titration of 20 ml of 0.5 molar sodium carbonate

solution till complete reaction.

(23) Find out the mass of sodium hydroxide present in 25 ml solution

which consumes, by titration, 15 ml of 0.1 molar hydrochloric acid

solution.

(24) On oxidation of 0.5 gram of magnetite ore (Fe3O4) into iron (III)

oxide, a 0.411 grams of Fe2O3 are produced. Calculate the % of the

black oxide (Fe3O4) in the ore.

(25) A two gram portion pf impure sodium chloride was dissolved in

water. Excess of silver nitrate was added to precipitate 4.628 grams

of silver chloride. Calculate the % of chlorine-in the Sample.



Question of general secondary examination

(A) Write the scientific expression for each of the following sentences:

1- The volumes of gases involved in a reaction and the gases

produced exist in fixed ratios. Aug. 2006

2- Equal volumes of gases under the same conditions of pressure and

temperature contain equal numbers of molecules. Aug. 2007

(B) Answer the following problems:

1. Calculate the density of oxygen gas (O2) at (STP). The atomic

mass of oxygen is 16. M a y 2 0 0 6

2. Four grams of impure podium chloride was dissolved in water

and an excess of silver nitrate solution was added to precipitate

9.256 grams of silver chloride.

Calculate the percentage of sodium chloride in the sample.

(Na = 23, CI = 35.5, and Ag = 108) May 2006

3. Hydrazine (N2H4) is used as a fuel for some rockets. Calculate the

mass of nitrogen gas produced from oxidation of 20 grams of

hydrazine. [N = 14, H = 1] A u g . 2 0 0 6

4. Calculate the volume of 0.1 mole of CO2 gas at SIR Aug. 2006

5. To obtain the iron in the blast furnace, carbon monoxide reduces

iron (III) oxide and if the haematite ore contains 45% of iron (III)

oxide. How many kilograms of haematite ore are required to

produce 1000 kilograms (one ton) of iron?

[Fa = 56, O = 16] May 2007



6. 0.2g of a mixture of solid substance containing sodium hydroxide

and sodium chloride was titrated with 0.1 molar of hydrochloric

acid. The complete reaction takes place by the consumption of 10

ml of the acid. Calculate the percentage of sodium hydroxide in

the mixture. [Na = 23,O = 16, and H = 1] May 2007

7. Calculate the number of ions produced by dissolving 7.1 grams of

sodium sulphate (Na2SO4) in water.

[Na = 23, S = 32, O = 16] Aug. 2007

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