25
NAME: _________________________________________ DATE: ____________ 1. What gas is formed when Zn metal is mixed with hydrochloric acid, HCl? a) CO 2 c) O 2 b) He d) H 2 2. Which property is always conserved during a chemical reaction? a) mass c) pressure b) volume d) solubility 3. A cylinder is weighed empty and with a liquid. Cylinder with liquid 51.85 g Cylinder, empty 40.11 g Volume of liquid in cylinder 7.0 mL What is the density of the liquid? a) 13 g/mL c) 5.7 g/mL b) 7.4 g/mL d) 1.7 g/mL 4. Which one of the following is the correct formula for aluminum oxide? a) AlO c) Al 2 O 3 b) Al 6 O 6 d) Al 3 O 2 5. What is the name of the compound CF 4 ? a) fluorocarbonate b) carbon tetrafluoride c) tricarbo fluoride d) carbon difluorate 6. Sodium nitride has the formula Na 3 N. What is the formula for magnesium nitride? a) Mg 2 N c) Mg 3 N 2 b) Mg 3 N d) Mg 2 N 3 7. What is the mass of one mole of aluminum sulfate, Al 2 (SO 4 ) 3 ? a) 630 g c) 273 g b) 342 g d) 123 g 8. Which set of coefficients balances the equation for the complete combustion of ethane, C 2 H 6 ? __C 2 H 6 + __O 2 __CO 2 + __H 2 O a) 1,3,2,3 c) 2,6,4,5 b) 1,6,2,6 d) 2,7,4,6 9. When this expression is balanced,

Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

  • Upload
    lycong

  • View
    229

  • Download
    8

Embed Size (px)

Citation preview

Page 1: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

NAME: _________________________________________ DATE: ____________1. What gas is formed when Zn metal is mixed with hydrochloric acid, HCl?

a) CO2 c) O2b) He d) H2

2. Which property is always conserved during a chemical reaction?a) mass c) pressureb) volume d) solubility

3. A cylinder is weighed empty and with a liquid.Cylinder with liquid 51.85 gCylinder, empty 40.11 gVolume of liquid in

cylinder7.0 mL

What is the density of the liquid?a) 13 g/mL c) 5.7 g/mLb) 7.4 g/mL d) 1.7 g/mL

4. Which one of the following is the correct formula for aluminum oxide?a) AlO c) Al2O3b) Al6O6 d) Al3O2

5. What is the name of the compound CF4?

a) fluorocarbonateb) carbon tetrafluoridec) tricarbo fluorided) carbon difluorate

6. Sodium nitride has the formula Na3N. What is the formula for magnesium nitride?a) Mg2N c) Mg3N2b) Mg3N d) Mg2N3

7. What is the mass of one mole of aluminum sulfate, Al2(SO4)3?

a) 630 g c) 273 gb) 342 g d) 123 g

8. Which set of coefficients balances the equation for the complete combustion of ethane, C2H6?__C2H6 + __O2 __CO2 + __H2O

a) 1,3,2,3 c) 2,6,4,5b) 1,6,2,6 d) 2,7,4,6

9. When this expression is balanced,2C3H6 + O2 CO2 + 6H2Owhat is the coefficient of oxygen, O2?

a) 6 c) 12b) 9 d) 18

10. During a “titration lab,” an acid was neutralized by the following reaction:NaOH + HCl NaCl + H2OThis reaction would be classified as…a) synthesisb) decomposition

Page 2: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

c) double replacementd) single replacement

11. Which reaction below would be classified as a decomposition reaction?a) NaHCO3 NaOH + CO2

b) 2 H2 + O2 2 H2Oc) 2 AgNO3 + Cu° Cu(NO3)2 + 2 Ag°d) Ba(OH)2 + H2SO4 BaSO4 + 2 H2O

12. The complete combustion of ethane, C2H6, producesa) C2H5OH c) CO2 and H2b) CH3COOH d) CO2 and H2O

13. What quantity of sulfur dioxide, SO2 (64.0 g/mole), is produced when 245 g of sulfuric acid, H2SO4 (98.0 g/mole) reacts completely with zinc metal?Zn° + 2 H2SO4 ZnSO4 + SO2 + 2 H2O

a) 64.0 g c) 128 gb) 80.0 g d) 160 g

14. How many moles of FeS2 are required to produce 64 grams of SO2 according to the equation4FeS2(s) + 11O2(g) 2Fe2O3(s) + 8SO2(g)

a) 0.40 c) 3.2b) 0.50 d) 4.5

15. Glass, SiO2, reacts with hydrofluoric acid, HF, according to this equationSiO2 + 4 HF 2 H2O + SiF4

Which reagent is completely consumed when 2 moles of SiO2 is added to 6 moles of HF?a) SiF4 c) HFb) H2O d) SiO2

16. Which of the following is an acid?a) NaOH c) HClb) NH3 d) KOH

17. The acid, H2S, is correctly named as:a) hydrosulfuric acidb) sulfuric acidc) dihydrogen sulfide d) hydrogen(I) sulfide

18. Hydrogen gas was produced according to the following equation:Zn° + 2 HCl ZnCl2 + H2

Which chemical is oxidized?a) Zn° c) ZnCl2b) HCl d) H2

Page 3: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Table of common polyatomic ions, arranged by charge.

2+Hg2

2+ mercury(I) or mercurous

1+NH4

+ ammonium

H3O+ hydronium

1-CH3COO- acetate

ClO3- chlorate

ClO2- chlorite

CN- cyanide

H2PO4- dihydrogen phosphate

HCO3- hydrogen carbonate or

bicarbonateHSO4

- hydrogen sulfate or bisulfateOH- hydroxide

ClO- hypochlorite

NO3- nitrate

NO2- nitrite

ClO4- perchlorate

MnO4- permanganate

SCN- thiocyanate

2-CO3

2- carbonate

CrO42- chromate

Cr2O72- dichromate

HPO42- hydrogen

phosphate

O22- peroxide

SO42- sulfate

SO32- sulfite

S2O32- thiosulfate

3-PO4

3- phosphate

SOLUBILITY RULES:Salts containing the following ions are normally soluble:

All salts of group IA (Li+, Na+, etc) and the ammonium ion (NH4+) are soluble.

All salts containing nitrate (NO3-)acetate ( CH3COO-), and perchlorates are

soluble. All chlorides (Cl-), Bromides (Br-), and iodides(I-) are soluble except those of

Cu+, Ag+, Pb2+, and Hg22+

All salts containing sulfate (SO42-) are soluble except those of Pb2+, Sr2+, and

Ba2+.

Salts containing the following ions are normally insoluble: Most carbonates (CO3

2-) and phosphates (PO43-) are insoluble except those of

group IA and the ammonium ion. Most sulfides (S2-) are insoluble except those of group IA and IIA and the

ammonium ion. Most hydroxides (OH-) are insoluble except those of group IA, calcium,

strontium, and barium. Most oxides (O2-) are insoluble except those of group IA, and calcium,

strontium, and barium which react with water.

Page 4: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Exercise #3 Types of CompoundsNAMING

Type of Compound

Ionic Acids Molecular

How To Recognize

metal + non-metal starts with H + anion two non-metals

How To Name names of + ion then - ion

“ides” hydro---ic acid“ates” ----ic acid

S (add “ur”) P (add “or”)

mono, di, tri, tetra, penta, hexa, hepta, octa, nona ,deca

names ends with “ide”pentaoxide pentoxide, etc.

Indicate the Type of Compound and then name the compound using the appropriate rules:

1. NaF ___ __________________

2. FeCl3 ___ __________________

3. CO2 ___ __________________

4. MgCl2 ___ __________________

5. HF ___ __________________

6. SF4 ___ __________________

7. HC2H3O2 ___ __________________

8. H2O ___ __________________

9. NH3 ___ __________________

10. CaO ___ __________________

11. NH4NO3 ___ __________________

12. NaI ___ __________________

13. PbCO3 ___ __________________

14. Na2O ___ __________________

15. Ba(NO3)2 ___ __________________

16. K2CrO4 ___ __________________

17. NO ___ __________________

18. HCl ___ __________________

21. CuCl2 ___ __________________

22. AgNO3 ___ __________________

23. CO ___ __________________

24. H3PO4 ___ __________________

25. NaCl ___ __________________

26. N2O5 ___ __________________

27. NO2 ___ __________________

28. HNO3 ___ __________________

29. NaOH ___ __________________

30. SnCl2 ___ __________________

31. CaSO4 ___ __________________

32. HBr ___ __________________

33. Cu(OH)2 ___ __________________

34. Zn(OH)2 ___ __________________

35. BaCl2 ___ __________________

36. PCl5 ___ __________________

37. PCl3 ___ __________________

38. AsF5 ___ __________________

39. H2CO3 ___ __________________

40. OF2 ___ __________________

Page 5: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

19. MnO2 ___ __________________

20. H2S ___ __________________

Exercise #4 Chemical Equations and Stoichiometry

W R I T I N G I O N I C C O M P O U N D SIonic compounds are formed from a positive ion (cation) and a negative ion (anion).The positive ion is always written first.The resulting compound must be electrically neutral.Use parentheses when you need two or more polyatomic ions in a formula.

Cl OH S2 CO32 PO4

3

Na+

NH4+

Ca2+

Al3+

Sn4+

Hg22+

Naming ionic compounds is easy. The name is simply the name of the cation, followed by the name of the anion.

# Name Cation Anion Formula1. ammonium phosphate NH4

+ PO43-

2. barium nitrate Ba2+ NO3-

3. cuprous sulfide or copper (I) sulfide Cu+ S2-

4. aluminum carbonate Al3+ CO32-

5. strontium hydroxide Sr2+ OH-

Exercise #6 2f: Inorganic Nomenclature II

Page 6: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Add either a name or a formula to complete each table.

1. Potassium dichromate 

2. Lithium sulfide 

3. Potassium bromide 

4. Cesium iodide 

5. Calcium phosphide 

6. Sodium fluoride 

7. Strontium oxide 

8. Beryllium sulfide 

9. Magnesium bromide 

10. Lithium oxide 

11. Strontium chloride 

12. Barium bromide 

13. Magnesium sulfide 

14. Magnesium iodide 

15. Hydrogen fluoride (Hydrogen monofluoride)

16. Barium phosphide 

17. Sodium hydrogen phosphate 

18. Potassium chloride

19. Lithium nitride

20. Calcium sulfide

21. Rubidium oxide

22. Strontium nitride

23. Cesium phosphide

24. Magnesium carbonate 

25. Beryllium sulfate 

26. ScCl3

27. HCl

28. PtO2

29. Sb(ClO3)5

30. GeS2 

31. ZnO

Page 7: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

32. VSO4

33. CuCl2 

34. TiO2

35. NiN

36. Ni3(PO4)2

37. CoF3

38. Au2O3

39. Zn3P2

40. Cr(NO3)6  

41. NaIO2

42. NaIO3

43. NaI

44. H2SO3

45. H2CO3

46. AlN

47. AlH3

48. Li3AsO4

49. NaCN

50. Na2O2

Page 8: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Exercise #7: Balancing Equations I Balance the following equations.

1. H2 + O2 H2O

2. H3PO4 + NaOH Na3PO4 + H2O

3. Na + B2O3 Na2O + B

4. HCl + KOH KCl + H2O

5. K + KNO3 K2O + N2

6. C + S CS2

7. Na + O2 Na2O2

8. N2 + O2 N2O4

9. H3PO4 + Ca(OH)2 Ca3(PO4)2 + H2O

10. KOH + H2CO3 K2CO3 + H2O

11. NaOH + HBr NaBr + H2O

12. H2 + O2 H2O2

13. K + O2 K2O

14. Al(OH)3 + H2SO3 Al2(SO3)3 + H2O

15. Al + S8 Al2S3

16. Li + N2 Li3N

17. Ca + Cl2 CaCl2

18. Rb + RbNO3 Rb2O + N2

19. C6H12 + O2 CO2 + H2O

20. N2 + H2 NH3

Page 9: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Exercise #8: Stoichiometry Summary

TYPE 1: Those involving Avogadro’s number.

Question 1

A sample of Ag is found to contain 9.7 x 1023 atoms Ag. How many moles of Ag atoms are in the sample?

Question 2

How many Sb atoms are found in 0.43 moles of pure Sb?

TYPE 2: Those involving the relationship between mass, moles and molar mass.

Question 3

What is the mass in grams of 2.53 moles Al?

Question 4

How many moles of Na in 20g of Na?

Question 5

If 50 moles of a simple, binary, group I chloride have a mass of 3725g identify the group I metal.

TYPE 3: Those combining types 1 & 2.

Question 6

How many Zr atoms are found in a 1.23g sample of Zr?

Question 7

What is the mass of 5.14 x 1023 atoms of uranium?

Question 8

What mass of C atoms have the same number of atoms as are in a 11.2g sample of Si?

TYPE 4: % by mass Composition.

Question 9

Page 10: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Calculate the percent by mass composition of ethanol, C2H6O.

Question 10

What is the percent by mass composition of N2O5?

Question 11

A compound has the formula Al4[Fe(CN)6]3. What is the percent by mass composition of this compound?

TYPE 5: Empirical formulae.

Question 12

A compound contains 26.9% N and 73.1% F. What is the empirical formula of the compound?

Question 13

2.3g of magnesium is completely reacted with 6.75g of chlorine. What is the empirical formula of the compound formed?

TYPE 6: Molecular formulae from empirical formulae.

Question 14

What is its molecular formula of hydrocarbon that has an empirical formula of C2H5 and a molecular mass of 58.

Question 15

A compound contains 68.54% carbon, 8.63% hydrogen, and the remainder oxygen. The molecular weight of this compound is approximately 140g/mol. What is the empirical formula? What is the molecular formula?

Type 7: Combustion Analysis.

Question 16

The combustion of 2.95 grams of a compound that contains only C, H and S yields 5.48 grams of CO 2 and 1.13 grams of H2O. What is the empirical formula of the compound?

Page 11: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Question 17

If, in the reaction below, of 31 grams of C4H10 produces 41 grams of CO2 what is the % yield?

2C4H10 + 13O2 8CO2 + 10H2O

Question 18

If, in the reaction below, 80.1 grams of Cl2 produces 33.12 grams of CCl4 what is the % yield?

CS2 + 3Cl2 CCl4 + S2Cl2

Type 9: Limiting Reactant.

Question 19

Consider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal.

a) Write an equation for the reaction.b) If 1240g of Al are reacted with 6010g of Iron (III) oxide, identify the limiting reagent. Which

reagent is in excess?c) Calculate the mass of Iron formed.d) How much of the excess reagent is left over at the end of the reaction?

Type 10: Analysis of hydrated salts.

Question 20

Copper (II) sulfate is found as a hydrated salt, CuSO4.xH2O. A technician carefully heats 2.50g of the salt to a

constant mass of 1.60g.

a) What is meant by constant mass?b) How many moles of copper sulfate are there in 1.60g of anhydrous copper (II) sulfate?c) How many moles of water were lost?

d) What is the value of x in the formula? Type 11: Moles and reacting ratios (including solutions).

Question 21

Sodium hydrogen carbonate, NaHCO3, combines with HCl as indicated below.

NaHCO3(aq) + HCl(aq) NaCl(aq) + CO2(g) + H2O(l)

a) What volume of 1.5M HCl solution should be present to combine totally with 0.14 moles of NaHCO3?b) How many moles of CO2 are produced when 0.49 g of NaHCO3 combines with excess HCl?c) Calculate the mass of NaCl that results when 1.48 moles of HCl combines with excess NaHCO3.d) What mass of NaHCO3 is required to produce 6.1 x 103 moles of H2O?

Question 22

Page 12: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

Carbon tetrachloride, CCl4, can be produced in the reaction below.

CH4 + 4Cl2 CCl4 + 4HCl

a) What mass of CH4 is needed to exactly combine with 3.4 g Cl2?b) How many grams of Cl2 are required to produce 91 g CCl4, assuming excess CH4?c) What mass of CH4 must have reacted, if 2 mg HCl is liberated?d) Calculate the mass of both CH4 and Cl2 required to produce exactly 0.761 kg CCl4?

Exercise #10: Writing chemical equations

Write balanced equations for the following reactions. Where possible include state(g, l, s) symbols.

1. Pure, molten iron forms when solid iron (III) oxide reacts with carbon monoxide gas. Carbon dioxide gas is also a product.

2. Potassium oxide reacts with water to produce potassium hydroxide.

3. During photosynthesis glucose (C6H12O6) forms from carbon dioxide and water. Oxygen is also a

product.

4. Sodium phosphate and barium sulfate are made during a reaction between sodium sulfate and barium phosphate.

5. Ammonium nitrate can decompose explosively to form nitrogen, water and oxygen.

6. The combustion (combination with oxygen) of liquid octane (C3H8) produces gaseous carbon dioxide and steam.

7. The combination of sodium metal and chlorine gas yields solid sodium chloride.

8. Hydrogen gas forms when magnesium metal comes in contact with an aqueous solution of ethanoic acid (CH3COOH). An aqueous solution of magnesium ethanoate Mg (CH3COO)2 is the other product.

9. The decomposition of solid copper (II) nitrate yields solid copper (II) oxide and nitrogen dioxide, and oxygen gases.

10. Solid mercury (II) oxide forms from the uncombined elements. Mercury is a liquid at room temperature.

Page 13: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

11. Magnesium metal and steam combine to form solid magnesium hydroxide and hydrogen gas.

12. An aqueous solution of hydrogen peroxide (H2O2) and solid lead (II) sulfide combine to form solid lead (II) sulfate and water.

13. Solid Sodium reacts with liquid water to produce aqueous sodium hydroxide and hydrogen gas.

14. Zinc reacts with silver nitrate to produce silver and zinc nitrate.

15. Aluminum sulfate reacts with calcium chloride to produce aluminum chloride and calcium sulfate.

16. Solid potassium hydroxide pellets decompose on heating to form solid potassium oxide and water.

Name_____________________Period __ Date __/__/__

Exercise #9_Chemical Equations and StoichiometryC O M B U S T I O N E Q U A T I O N S

For burning to occur, you need a fuel, an oxidizer, and heat. When hydrocarbons are the fuel and

O2 in the air is the oxidizer, then CO2 and H2O are the products.

Example: Write the balanced equation for the complete combustion of propane, C3H8, in air.

Solution: First, set up the basic equation. You memorize the “+ O2 CO2 + H2O” part.

C3H8 + O2 CO2 + H2O

Next, balance. 3 C’s in C3H8 result in 3CO2’s; 8 H’s in C3H8 result in 4 H2O’s;

C3H8 + __ O2 3 CO2 + 4 H2O

Total O’s on the product side = 10 [(3 x 2) + (4 x 1)] = total O’s on the

reactant side.

This would mean that 5 O2’s were involved.

Tip: If an UNEVEN number of O’s need to be represented, a fraction should be used. 7 O’s = 7/2

O2

Tip: Take into account fuels that contain oxygen. Subtract the O’s from that represented as O2’s

Practice: Write the balanced combustion equations for the following substances.

Page 14: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

1. CH4

2. C5H12

3. C9H20

4. C2H6

5. C8H18

6. C4H10

7. C2H5OH

8. C3H7OH

9. HC2H3O2

10. CH3COCH3

Name_________________________________Period ___ Date ___/___/___

Exercise #11 Acids & BasesT I T R A T I O N P R A C T I C E

An acid and a base neutralize each other when the moles of H+ = the moles of OH. A formula similar to the dilution formula can be used to determine the concentration of an unknown acid or base.

VaMa=VbMb where a = H+ b = OH-

Example: What is the concentration of a 10.0 mL sample of HCl if 35.5 mL of 0.150 M NaOH is needed to titrate it to a pink endpoint?

(10.0 mL) (x) = (35.5 mL) (0.150 M)

x = = 0.5325 M = 0.533 M

1. What is the concentration of a 15.0 mL sample of HCl if 28.2 mL of 0.150 M NaOH is needed to titrate it?

Page 15: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

2. A 10.0 mL sample of a monoprotic acid is titrated with 45.5 mL of 0.200 M NaOH. What is the concentration of the acid?

3. A 5.00 mL sample of vinegar has a concentration of 0.800 M. What volume of 0.150 M NaOH is required to complete the titration?

4. A 10.0 sample of household ammonia, NH3(aq), is titrated with 0.500 M HCl. If 25.7 mL of acid is required, what is the concentration of the household ammonia?

5. A 5.00 mL sample of H2SO4 is titrated with 0.150 M NaOH. If 20.0 mL of the base is required to titrate the acid sample, what is the [H+] of the acid? ________ What is [H2SO4]? _________

12 The Gas LawsT H E I D E A L G A S L A W

PV = nRT whereP = pressure in atmosphereV = volume in litersn = number of moles of gasR = Universal Gas Constant = 0.0821

Latm/molKT = Kelvin temperature

1. What is the pressure of 1.20 moles of SO2 gas in a 4.00 L container at 30°C?

2. How many moles of oxygen will occupy a volume of 2.50 liters at 1.20 atm and 25 C?

Page 16: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

3. What is the volume of 0.60 moles of helium gas at 50°C if the pressure is 600 torr?

4. At what temperature will 1.80 moles of gas occupy 4.00 L if the pressure is 350 mmHg?

5. A balloon filled with helium has a volume of 1.30 L at 15°C when the atmospheric pressure is 700 torr. How many molecules of helium is in the balloon?

6. What is the mass of a 300 mL sample of gaseous hydrogen chloride at 2.0 atm and 30°C? . m = µPV/RT where m is mass in grams and µ is molar mass

What is the density of this sample? D = m/V where D is density in grams per Liter

7. A 30.0 g sample of CH4 occupies 150 mL at 0°C. What is the pressure of this sample of gas?

P = mRT/Vµ

8. What volume (in liters) does a 85.0-g sample of CO2 gas occupy at 1.40 atm and 80°C?

Page 17: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

V = mRT/µP

What is the density of this gas? D = m/V

9. How many moles of an unknown diatomic gas are contained in a 500 mL container at 1.20 atm and 25°C?

If this unknown diatomic gas has a mass of 0.93 g, what is the molar mass of the gas? What is the gas?

µ = g/mol

12 The Gas LawsB O Y L E ’ S L A W

Boyle’s Law states that the volume of a gas varies inversely with its pressure if temperature is held constant.

(If one goes up, the other goes down.) We use the formula:

P1 V1 = P2 V2

Solve the following problems (assuming constant temperature). Assume all number are 3 significant figures.

1. A sample of oxygen gas occupies a volume of 250 mL at 740 torr pressure. What volume will it occupy at 800 torr pressure?

2. A sample of carbon dioxide occupies a volume of 3.50 Liters at 125 kPa pressure. What pressure would the gas exert if the volume was decreased to 2.00 liters?

Page 18: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

3. A 2.00-Liter container of nitrogen had a pressure of 3.20 atm. What volume would be necessary to decrease the pressure to 1.00 atm?

4. Ammonia gas occupies a volume of 450 mL as a pressure of 720 mmHg. What volume will it occupy at standard pressure (760 mmHg)?

5. A 175 mL sample of neon had its pressure changed from 75.0 kPa to 150 kPa. What is its new volume?

6. A sample of hydrogen at 1.50 atm had its pressure decreased to 0.50 atm producing a new volume of 750 mL. What was the sample’s original volume?

7. Chlorine gas occupies a volume of 1.20 liters at 720 torr pressure. What volume will it occupy at 1 atm pressure?

8. Fluorine gas exerts a pressure of 900 torr. When the pressure is changed to 1.50 atm, its volume is 250 mL. What was the original volume?

12 The Gas LawsC H A R L E S ’ S L A W

Charles’ Law states the volume of a gas varies directly with the Kelvin temperature, assuming the pressure is constant. We use the following formulas:

2

2

1

1

TV

TV

or V1 T2 = V2 T1

K = C + 273

Solve the following problems assuming a constant pressure. Assume all numbers are 3 significant figures.

1. A sample of nitrogen occupies a volume of 250 mL at 25 C. What volume will it occupy at 95 C?

2. Oxygen gas is at a temperature of 40 C when it occupies a volume of 2.30 Liters. To what temperature should it be raised to occupy a volume of 6.50 Liters?

Page 19: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

3. Hydrogen gas was cooled from 150 C to 50 C. Its new volume is 75.0 mL. What was its original volume?

4. Chlorine gas occupies a volume of 25.0 mL at 300 K. What volume will it occupy at 600 K?

5. A sample of neon gas at 50 C and a volume of 2.50 Liters is cooled to 25 C. What is the new volume?

6. Fluorine gas at 300 K occupies a volume of 500 mL. To what temperature should it be lowered to bring the volume to 300 mL?

7. Helium occupies a volume of 3.80 Liters at –45 C. What volume will it occupy at 45 C?

8. A sample of argon gas is cooled and its volume went from 380 mL to 250 mL. If its final temperature was –55 C, what was its original temperature?

12 The Gas LawsT H E C O M B I N E D G A S L A W

In practical terms, it is often difficult to hold any of the variables constant. When there is a change in pressure, volume and temperature, the combined gas law is used.

2

22

1

11

TVP

TVP

or P1 V1 T2 = P2 V2 T1

K = C + 273

Complete the following chart.

P1 V1 T1 P2 V2 T2

1 1.50 atm 3.00 L 20.0 C 2.50 atm 30.0 C

2 720. torr 256. mL 25.0 C 250. mL 50.0 C

Page 20: Possible Practice Final Exam - Alvord Unified School … · Web viewConsider the reaction between Aluminum and Iron (III) oxide to produce Aluminum oxide and Iron metal. Write an

3 600. mmHg 2.50 L 22.0 C 760. mmHg 1.80 L

4 750. mL 0.00 C 2.00 atm 500. mL 25.0 C

5 95.0 kPa 4.00 L 101. kPa 6.00 L 471. K or 198. C

6 650. torr 100. C 900. torr 225. mL 150. C

7 850. mmHg 1.50 L 15.0 C 2.50 L 30.0 C

8 125. kPa 125. mL 100. kPa 100 mL 75.0 C

Oxidation Numbers:1) In which reaction does the oxidation number of oxygen increase? A) B) HCl (aq) + NaOH (aq) → NaCl (aq) + C) D) E) 2) In which reaction does the oxidation number of hydrogen change? A) HCl (aq) + NaOH (aq) → NaCl (aq) + B) C) D) E) 3) In which species does sulfur have the highest oxidation number? A) (elemental form of sulfur) B) C) D) E)