A pharmaceutical company makes aspirin by reacting salicylic acid with ethanoic anhydride. It carries out the same reaction under two different sets of conditions, P and Q, and records these results.
| Conditions | Atom economy | Percentage yield |
|---|---|---|
| P | 75 % | 82 % |
| Q | 75 % | 57 % |
Which statement is correct?
The equation turns the same percentage of reactant mass into aspirin for P and Q, and P obtains more of the maximum possible aspirin.
The equation turns a greater percentage of reactant mass into aspirin for P, and P obtains more of the maximum possible aspirin.
P and Q obtain equal proportions of the maximum possible aspirin, because the equation turns the same percentage of reactant mass into aspirin.
Q wastes a smaller percentage of reactant mass as by-products, because Q obtains less of the maximum possible aspirin.
104 exam-style questions on AQA GCSE Chemistry 3.3 Yield and atom economy of chemical reactions, covering 3.3.1a Percentage yield, 3.3.1b Theoretical mass of a product, 3.3.2a Atom economy, and 3.3.2b Choosing a reaction pathway. Each one has a worked solution and a mark scheme showing where the marks go.