Percentage Yield

Question

Gaseous methane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water . If 3.56 g of carbon dioxide is produced from the reaction of 1.8 g of methane and 9.6 g of oxygen gas, calculate the percent yield of carbon dioxide.

Be sure your answer has the correct number of significant digits in it.

Answer 1

The percent yield of carbon dioxide produced is 100% x (actual yield/theoretical yield). We already have the actual yield of carbon dioxide (3.56g) so we just need to find the theoretical yield.

1) We have to write the balanced equation: CH₄+2O₂----> CO₂ +2H₂O

2) Convert 1.8 g of methane and 9.6 g of oxygen gas to moles in order to find the limiting reactant.

*1.8g CH₄ x (1 mol CH₄)/(16 g CH₄)= 0.1125 mol CH₄

*9.6g O_2. x (1 mol O₂)/ (32g O₂)= 0.3 mol O₂

CH₄ is the limiting reactant

3) Convert mol of CH₄ to g of CO₂ in order to find the theoretical yield.

0.1125 mol CH₄ x (1 mol CO₂)/(1 mol CH₄) x (44 g CO₂)/ (1 mol CO₂)= 4.95 g CO2

4) Use the percent yield formula: 100% x(3.56 g CO₂)/(4.95g CO₂)= 71.8 %