Problem One
1. For the balanced equation C3H6+3O2=>3CO+3H2O,
if the reaction of 21.3 grams of O2 produces a 47.3% yield, how many grams of CO would be produced ?
Step One: Figure out how many moles of the limiting reagent you have
O * 2 = 16 * 2 = 32 grams/mole
21.3 grams = 0.66 moles
32 g/m
Step Two: Determine how many moles of product would be formed
0.66 moles * (3 moles of CO2 / 3 moles of O2) = 0.66 moles
Step Three: Multiply your result by the molar mass of the product
0.66 moles * (28 g/m) = 18.48
Step Four: Solve for the actual yield
47.3 % = (actual yield) * 100
18.48 grams
Actual yield = 8.74 grams
Problem Two
2. For the balanced equation 2C6H6+15O2=>12CO2+6H2O,
if the reaction of 9.86 grams of C6H6 produces 4.52 grams of H2O, what is the percent yield?
Step One: Figure out how many moles of the limiting reagent you have
C * 6 = 12 * 6 = 72
H * 6 = 1 * 6 = 6
72 + 6 = 78 grams/mole
9.86 grams = 0.126 moles
78 g/m
Step Two: Determine how many moles of product would be formed
0.126 moles * (6 moles of H2O / 2 moles of C6H6) = 0.379 moles
Step Three: Multiply your result by the molar mass of the product
0.379 moles * (18 g/m) = 6.826 grams
Step Four: Solve for the percent yield
percent yield = 4.52 grams * 100
6.826 grams
percent yield = 66.21%
Problem Three
3. For the balanced equation 2C2H3O2F+3O2=>4CO2+2H2O+2HF,
if the reaction of 24.1 grams of O2 produces a 55.7% yield, how many grams of HF would be produced ?
Step One: Figure out how many moles of the limiting reagent you have
O * 2 = 16 * 2 = 32 grams/mole
24.1 grams = 0.753 moles
32 g/m
Step Two: Determine how many moles of product would be formed
0.753 moles * (2 moles of HF / 3 moles of O2) = 0.502
Step Three: Multiply your results by the molar mass of the product
H * 1 = 1 * 1 = 1
F * 1 = 19 * 1 = 19
1 + 19 = 20 grams/mole
0.502 moles * (20 g/m) = 10.041 grams
Step Four: Solve for the actual yield
55.7 yield = (actual yield) * 100
10.041 grams
Actual Yield = 5.59%
Problem Four
4. For the balanced equation 2C4H8O+11O2=>8CO2+8H2O,
if the reaction of 54.7 grams of O2 produces 16.0 grams of H2O, what is the percent yield?
Step One: Figure out how many moles of the limiting reagent you have
O * 2 = 16 * 2 = 32 g/m
54.7grams = 1.709 moles
32g/m
Step Two: Determine how many moles of product will be formed
1.709 moles * (8 moles of H2O / 11 moles of O2) = 1.243 moles
Step Three: Multiply your results by the molar mass of the product
1.243 moles * (18 g/m) = 22.377 grams
Step Four: Solve for percent yield
percent yield = 16 grams * 100
22.377 grams
percent yield = 71.5%
Problem Five
5. For the balanced equation Fe3O4+4H2=>3Fe+4H2O,
if the reaction of 24.8 grams of H2 produces a 63.7% yield, how many grams of H2O would be produced ?
Step One: Figure out how many moles of the limiting reagent you have
H * 2 = 1 * 2 = 2
24.8 grams = 12.4 moles
2 g/m
Step Two: Determine how many moles of product will be formed
12.4 moles * (4 moles of H2O / 4 moles of H2) = 12.4 moles
Step Three: Multiply your results by the molar mass of the product
12.4 moles * (18 g/m) = 223.2 grams
Step Four: Solve for actual yield
63.7 % = (actual yield) * 100
223.2 grams
actual yield = 142.17%
Problem Six
6. For the balanced equation 2NH3+CO2=>CO(NH2)2+H2O,
if the reaction of 81.9 grams of CO2 produces 26.7 grams of H2O, what is the percent yield?
Step One: Figure out how many moles of the limiting reagent you have
C * 1 = 12 * 1 = 12
O * 2 = 16 * 2 = 32
12 + 32 = 44 grams/mole
81.9 grams = 1.86 moles
44 g/m
Step Two: Determine how many moles of product will be formed
1.86 moles * (1 mole of H2O / 1 mole of CO2) = 1.86 moles
Step Three: Multiply your results by the molar mass of the product
1.86 moles * (18 g/m) = 33.5 grams
Step Four: Solve for percent yield
percent yield = 26.7 grams * 100
33.5 grams
percent yield = 79.69%
Problem Seven
7. For the balanced equation K2O+H2O=>2KOH,
if the reaction of 27.5 grams of K2O produces a 69.5% yield, how many grams of KOH would be produced ?
Step One: Figure out how many moles of the limiting reagent you have
K * 2 = 40 * 2 = 78
O * 1 = 16 * 1 = 16
78 + 16 = 94 grams/mole
27.5 grams = 0.292 moles
94 g/m
Step Two: Determine how many moles of product will be formed
0.286 moles * (2 moles of KOH / 1 mole of K2O) = 0.585 moles
Step Three: Multiply your results by the molar mass of the product
0.585 moles * (56 g/m) = 532.76 grams
Step Four: Solve for actual yield
69.5 % = (actual yield) * 100
32.76 grams
actual yield = 22.77 grams
Problem Eight
8. For the balanced equation C6H5N2Cl=>C6H5Cl+N2,
if the reaction of 63.8 grams of C6H5N2Cl produces 8.35 grams of N2, what is the percent yield?
Step One: Figure out how many moles of the limiting reagent you have
C * 6 = 12 * 6 = 72
H * 5 = 1 * 5 = 5
N * 2 = 14 * 2 = 28
Cl * 1 = 35 * 1 = 35
72 + 5 + 28 + 35 = 140 grams/mole
63.8 grams = 0.455 moles
140 g/m
Step Two: Determine how many moles of product will be formed
0.455 moles * (1 mole of N2 / 1 mole of C6H5N2Cl) = 0.455 moles
Step Three: Multiply your results by the molar mass of the product
0.455 moles * (28 g/m) = 12.76 grams
Step Four: Solve for percent yield
Percent yield = 8.35 grams * 100
12.76 grams
Percent yield = 65.43%
Problem Nine
9. For the balanced equation 2C4H10O2+11O2=>8CO2+10H2O,
if the reaction of 94.4 grams of O2 produces a 72.3% yield, how many grams of H2O would be produced ?
Step One: Figure out how many moles of the limiting reagent you have
O * 2 = 16 * 2 = 32 grams/mole
94.4 grams = 2.95 moles
32 g/m
Step Two: Determine how many moles of product will be formed
2.95 moles * (10 moles of H2O / 11 moles of O2) = 2.68 moles
Step Three: Multiply your results by the molar mass of the product
2.68 moles * (18 g/m) = 48.27 grams
Step Four: Solve for actual yield
72.3 % = (actual yield) * 100
48.27 grams
actual yield = 34.9 %
Problem Ten
10. For the balanced equation 2C6H4Cl2+13O2=>12CO2+2H2O+4HCl,
if the reaction of 52.8 grams of O2 produces 31.7 grams of CO2, what is the percent yield?
Step One: Figure out how many moles of the limiting reagent you have
O * 2 = 16 * 2 = 32 grams/mole
52.8 grams = 1.65 moles
32 g/m
Step Two: Determine how many moles of product will be formed
1.65 moles * (12 moles of CO2 / 13 moles of O2) = 1.52 moles
Step Three: Multiply your results by the molar mass of the product
1.52 moles * (44 g/m) = 67.01 grams
Step Four: Solve for percent yield
percent yield = 31.7 grams * 100
67.01 grams
percent yield = 47.3 %