Moles

Moles

Like a recipe:

Reactants Products

2H2(g) + O2(g) 2H2O(l)

coefficients subscripts

Balancing Eqns

Moles

Symbols Yields or Produces(s) solid(l) liquid (pure liquid)(aq) aqueous (dissolved in water)(g) or gas

Balancing Eqns

Moles

Copper(II) Chloride reacts with Iron(III) Sulfate to form Copper(II)Sulfate and Iron(III) Chloride

Aluminum nitrate reacts with Sodium hydroxide to form Aluminum hydroxide and Sodium nitrate

Balancing

MolesSome Types of Reactions

1. Synthesis

Al + Cl2 AlCl3

CaO(s) + CO2(g) CaCO3(s)

2. Decomposition

HgO(s) Hg(l) + O2(g)

CaCO3(s) CaO(s) + CO2(g)

Moles

3. Combustion

Fe + O2 Fe2O3

C4H10 + O2 CO2 + H2O

4. Other TypesSingle ReplacementDouble Replacement

Some Types of Reactions

MolesKnow your reactions well!!!!

Moles

Mole

1 dozen = 12 items

1 mole = 6.022 X 1023 atoms/molecules

1 gram hydrogen = 6.022 X 1023 atoms of hydrogen

Stoichiometry

Moles

Moles

MolesStoichiometry

Grams Moles Atoms

1 g H 1 mole H 6.02 X 1023 atms

2 g H

12 g C

36 g C

48 g O

MolesStoichiometry

Grams Moles Molecules Atoms

16 g CH4

8 g CH4

88 g CO2

131 g Ba(NO3)2

Moles

1. Molar Mass = mass of one mole

2. Element= atomic mass

1 mole of O = 16.0 grams

3. Molecule or Compound – sum of all the atoms

Molar Mass

Moles

Moles

Calculate the molar mass of

Barium

O2

BaCl2?

Fe2(SO4)3?

Molar Mass

Moles

Grams

Moles

Atoms

1. How many C atoms are present in 18.0 g? (Ans: 9.03 X 1023 C)

2. What is the mass of 1.20 X 1024 atoms of Na? (Ans: 45.8 grams)

GMA

Moles

3. What is the mass of 1.51 X 1023 atoms of Be?(Ans: 2.26 g)

5. How many atoms and grams are in 0.400 mol of Radium? (Ans: 90.4 g, 2.41 X 1023 atoms)

GMA

Moles

1. Monoatomic Elements (C, Fe, Au)GMA

2. Molecules and Ionics (H2O, CaCl2, O2)GMMA

GMMA

Moles

3. Molecules and formula units work the same when convertingMolecules = Molecular CompsFormula Units = Ionic Compounds

GM M

A

GMMA

Moles

1. How many calcium and chlorine atoms are in 200.0 grams of Calcium Chloride?

(Ans: 2.17 X 1024 atoms Cl)

GMMA

Moles

2. How many hydrogen and oxygen atoms are in 3.60 grams of H2O? (Ans: 2.41 X 1023 atoms H)

GMMA

Moles

3. Given 3.01X1024 molecules of SO3, find everything else.

4. Given 3.01 X 1022 molecules of Iron(III)bromide, find everything else.

GMMA

Moles

1. How many carbon atoms are in 36.0 grams of carbon (1.81 X 1024)

2. How many carbon atoms are in 36.0 grams of C2H6? (Ans:1.45 X 1024 atoms of C)

Mixed Examples

Moles

Homework Problems (find everything else)

a) 10.0 g C

b) 10.0 g C2H6

c) 4.0 X 1023 atoms of S

d) 4.0 X 1023 molecules of SO2

e) 0.44 moles of SO2

Mixed Examples

Moles

1. Empirical formula - simplest ratio of the elements in a compound

2. Formula Empirical Form.

C2H2

Al4S6

C6H12O6

C12H24O12

Empirical Formula

Moles

1. What is the EF of a compound that has 0.900 g Ca and 1.60 g Cl?

Rules

- Go to moles

- Divide by the smaller

Empirical Formula

Moles

2. What is the EF of a compound that is 66.0 % Ca and 34.0% P?

3. What is the EF of a compound that is 43.7 % P and 56.3 % O?

Empirical Formula

Moles

1. Empirical –ratios of the elements2. Molecular –true number of each

element

Molecular Formula

Moles

EF MF

CH2O CH2O (30 g/mol)

C2H4O2 (60 g/mol)

C3H6O3 (90 g/mol)

C4H8O4 (120 g/mol)

Molecular Formula

Moles

1. What is the MF of benzene if it has an EF of CH and a molar mass of 78.0 g?

2. What is the MF of a compound that is 40.9% C, 4.58 % H and 54.5 % O? It has a molar mass between 350 and 360 g/mol.

Molecular Formula

Moles

What coefficients mean:

2 Na + Cl2 2NaCl

2 Na 1 Cl2 2NaCl

4 Na

6 Na

Reaction Stoich.

Moles

2 Na + Cl2 2NaCl

4 Cl2

2 moles Na

10 moles Na

ONLY WORKS FOR MOLES AND MOLECULES

Reaction Stoich.

Moles

1. How many moles of H2 and O2 must react to form 6 moles of H2O?

2. How many moles of KCl and O2 are formed from the decomposition of 6 moles of KClO3?

Reaction Stoich.

Moles

3. How many grams of oxygen are needed to react with 14.6 g of Na to form Na2O? (Ans: 5.08 g)

4. How many grams of P4 and O2 are needed to make 3.62 g of P2O5? (Ans: 1.58 g, 2.04 g)

Reaction Stoich.

Moles

5. What mass of oxygen is needed to react with 16.7 g of iron to form Iron(III)oxide? (Ans: 7.18 g)

4Fe + 3O2 2Fe2O3

Reaction Stoich.

Moles

Calculate the mass of sodium bromide and oxygen that are formed from the decomposition of 50.0 grams of sodium bromate (NaBrO3).

(34.1 g NaBr, 15.9 g O2)

Moles

1. Sandwich analogy:

13 slices of bread

4 pieces of turkey

Maximum # of sandwiches?

2. Limiting Reactant – Totally consumed in a reaction. No leftovers

Limiting Reactant

Moles

1. How many grams of H2SO4 can be formed from the rxn of 5.00 moles of SO3 and 2.00 moles of H2O?

SO3 + H2O H2SO4

(Ans: 196 g)

Limiting Reactant

Moles

1. How many grams of H2O can be formed from the rxn of 6.00 moles of H2 and 4.00 moles of O2?

O2 + H2 H2O

Limiting Reactant

Moles

2. How many grams of NaCl can be formed from the reaction of 0.300 mol of Na and 0.100 mol of Cl2?

2Na + Cl2 2NaCl

(Ans: 11.7 g)

Limiting Reactant

Moles

3. How many grams of Ag can be formed from the rxn of 2.00 g of Zn and 2.50 g of silver nitrate? How much excess reactant remains?

Zn + AgNO3 Ag + Zn(NO3)2

(Ans: 1.59 g Ag, 1.52 g xs zinc)

Limiting Reactant

Moles

4. How many grams of Ba3(PO4)2 can be formed from the rxn of 3.50 g of Na3PO4 and 6.40 g of Ba(NO3)2?

Na3PO4 + Ba(NO3)2 Ba3(PO4)2 + NaNO3

(Ans: 4.92 g)

Limiting Reactant

Moles

6. How many grams of Ag2S can be formed from the rxn of 15.6 g of Ag and 2.97 g of H2S? (Assume O2 is in excess)

4Ag + 2H2S + O2 2Ag2S + 2H2O

(Ans: 18.1 g)

Limiting Reactant

Moles

A. Formula:

Actual Yield X 100 = % Yield

Theoretical Yield

Percent Yield

Moles

1. What is the % yield if you start with 10.00 grams of C and obtain 1.49 g of H2 gas?

C + H2O CO + H2

(Ans: 89.4%)

Percent Yield

Moles

2. Carbon was heated strongly in sulfur(S8) to form carbon disulfide. What is the percent yield if you start with 13.51 g of sulfur and collect 12.5 g of CS2?

4C + S8 4CS2

(Ans: 78.0%)

Percent Yield

Moles

3. 36.7 grams of CO2 were formed from the rxn of 40.0 g of CH3OH and 46.0 g of O2. What is the % yield?

2CH3OH + 3O2 2CO2 + 4H2O

(ANS: 87%)

Percent Yield

Moles

MolesIn this experiment, magnesium chloride was prepared and its empirical formula was compared to the accepted formula of MgCl2. To prepare magnesium chloride, 0.40 grams of magnesium powder was combined with 10 mL of 0.10 M HCl. The mixture was allowed to react, and heated to dryness. The mass of the resulting crystals was used to calculate the empirical formula. The average calculated formula of MgCl1.8 had a 10% error and a range was 0.40 chlorine atoms. This procedure was not effective because while it was accurate, it was not precise.

Moles

8a) SO3 + H2O H2SO4

b) B2S3 + 6H2O 2H3BO3 + 3H2S

c) 4PH3 + 8O2 6H2O + P4O10

d) 2Hg(NO3)2 2HgO + 4NO2 + O2

e) Cu + 2H2SO4 CuSO4 + SO2 + 2H2O

Moles

12.a) 6 1 2 14. a) 1 1 1

b) 1 3 2 b) 1 6 2 3

c) 2 2 1 4 c) 1 2 2 1

d) 1 6 3 2 d) 2 2 4 1

e) 3 2 1 6 e) 1 2 1 1 2

f) 2 1 1 2

g) 4 9 4 10 2

Moles18.a) 4Al + 3O2 2Al2O3

b) Cu(OH)2 CuO + H2O

c) C7H16 + 11O2 7CO2 + 8H2O

d) 2C5H12O + 15O2 10CO2 + 12H2O

20. 2 9 6 6

1 1 2

1 6 5 3

1 3 2

1 1 2

22.a) 44.0 g/mol b) 122.0 g/mol

c) 58.3 g/mol d) 60.0 g/mol e) 130.0 amu

Moles24. 26.0 g/mole 92.3% C

176.0 g/mole 4.5% H

132.1 g/mole 6.1% H

300.1 g/mole 65.01% Pt

272.0 g/mole 11.8% O

305.0 g/mole 70.8 % C

Moles

46 a)K3PO4 b) Na2SiF6c) C12H12N2O3

48 a) H2C2O4 b) C4H8O2

50 a) C13H18O2 b) C5H14N2 c) C9H13O3N

Moles

58.a) 0.800 mol CO2 b) 14.7 g C6H12O6

c) 7.16 g CO2

60.a) 0.939 mol Fe2O3 b) 78.9 g CO

c) 105 g Fe d) 229 g= 229 g

Moles48.a) H2C2O4 b) C4H8O2

50. a) C13H8O2 b)C5H14N2

c) C9H13O3N

58.a) 0.800 mol CO2 b) 14.7 g C6H12O6

c) 7.18 g CO2

60.a) Fe2O3 + 3CO 2Fe + 3CO2

b) 78.9 g CO2

c) 124 g CO2

d) 229 g = 229 g

Moles62.a) CaH2 + 2H2O Ca(OH)2 + 2H2

b) 88.75 g CaH2

64. a) 15.6 mol O2 b) 35.0 g O2 c) 9175.1 g

72.0.167 mol Al2(SO4)3 form

0.333 mol Al(OH)3 react

0.167 mol AL(OH)3 remain

74.a) O2 is limiting reactant

b) 1.86 g H2O produced

c) 0.329 g NH3 remain

d) 4.25 g = 4.25 g

Moles76. 5.24 g H2SO4 6.99 g PbSO4

2.77 g HC2H3O2

78. C2H6 + Cl2 C2H5Cl + HCl

232 g C2H5Cl (theoretical yield)

88.8% yield

80. Actual yield of Na2S = 1.80 g (1.95 g is the theoretical yield)

Moles

The atmosphere of Jupiter is composed almost entirely of hydrogen (H2) and helium (He). If the average molar mass of Jupiter’s atmosphere is 2.254 g/mole, calculate the percent composition.

Moles