A student investigates the reaction between sodium thiosulfate solution and dilute hydrochloric acid.
The experiment is repeated using a higher concentration of sodium thiosulfate solution, keeping all other variables constant. The rate of reaction is found to be faster.
Explain, in terms of particles and collisions, why increasing the concentration of a reactant in solution increases the rate of reaction.
127 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.