Four cell extracts, W, X, Y and Z, contain enzymes that catalyse different reactions. Temperature and collision frequency are identical for W–Z. The reactant and peak energies for each enzyme-catalysed route are recorded below.
| Extract | Energy of reactants (kJ/mol\mathrm{kJ/mol}kJ/mol) | Energy at highest point (kJ/mol\mathrm{kJ/mol}kJ/mol) |
|---|---|---|
| W | 125 | 210 |
| X | 25 | 95 |
| Y | 175 | 230 |
| Z | 200 | 265 |
Which extract is likely to form its product at the lowest rate?
Extract Y
Extract X
Extract W
Extract Z
122 exam-style questions on OCR GCSE Chemistry 5.2 Controlling reactions, covering 5.2.1 Measuring and interpreting rate of reaction, 5.2.2 Factors affecting rate and collision theory, and 5.2.3 Catalysts, activation energy and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.