A student wants to follow the rate of four different reactions by measuring the loss in mass of the reaction flask. The balance reads to 0.01 g. The same total mass of reactants is used each time.
For which reaction is this method least suitable?
Calcium carbonate with hydrochloric acid, making carbon dioxide
Hydrogen peroxide with a catalyst, making oxygen
Zinc carbonate with sulfuric acid, making carbon dioxide
Magnesium with hydrochloric acid, making hydrogen
56 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.