A student reacts equal lengths of magnesium ribbon with the same volume of hydrochloric acid. The time taken to collect the first 30 cm3 of hydrogen is recorded.
| Hydrochloric acid | Time to collect 30 cm3 of hydrogen (s) |
|---|---|
| P | 72 |
| Q | 180 |
The rate of reaction is directly proportional to the concentration of the hydrochloric acid. All other conditions are the same.
How does the concentration of hydrochloric acid Q compare with the concentration of hydrochloric acid P?
Q has 0.4 times the concentration of P.
Q has 1.5 times the concentration of P.
Q has 2.5 times the concentration of P.
Q has 0.6 times the concentration of P.
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.