A student does two experiments at the same temperature.
Experiment 1: excess marble chips are added to 50 cm350\,\mathrm{cm^{3}}50cm3 of dilute hydrochloric acid.
Experiment 2: the same mass of the same-sized marble chips is added to 100 cm3100\,\mathrm{cm^{3}}100cm3 of hydrochloric acid that is half as concentrated.
How do the results of Experiment 2 compare with those of Experiment 1?
Initial rate is lower and total volume of gas is the same.
Initial rate is lower and total volume of gas is doubled.
Initial rate is the same and total volume of gas is the same.
Initial rate is the same and total volume of gas is doubled.
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.