A student makes three statements about catalysts.
Statement 1: A catalyst is chemically unchanged at the end of the reaction.
Statement 2: Only a small mass of catalyst is usually needed.
Statement 3: A catalyst increases the total mass of product made.
Which statements are correct?
1 and 2 only
1 and 3 only
2 and 3 only
1, 2 and 3
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.