Percentage yield is one of many deciding factors in determining whether or not a reaction is economically viable. It compares the experimental or actual mass of product made in a chemical reaction with the theoretical maximum mass possible – obviously, the higher the better!
Practice questions
- Calculate the % yield of the production of iron from iron oxide if 0.30 tonnes of iron are produced from 5.0 tonnes of iron oxide.
Fe2O3 + 3CO ⇾ 2Fe + 3CO2
- Calculate the % yield of copper oxide produced from the decomposition of 1.3 tonnes of copper carbonate, given that 0.45 tonnes of copper oxide are produced.
CuCO3 ⇾ CuO + CO2
Answers
- 5.0 tonnes of Fe2O3 is 0.0313mol; 1:2 ratio; 0.0627 mol of Fe is 3.50 tonnes (which is how much we should have made); % yield = 8.6%
- 1.3 tonnes of CuCO3 is 0.0105mol; 1:1 ratio; 0.0105 mol of CuO is 0.837 tonnes; % yield = 53.8%