The results recorded here show that the reaction had finished by four minutes, as no more gas was produced after that. The mean rate of reaction = 50 ÷ 4 = 12.5 cm 3 /min However, the rate decreased ...

The rate of a chemical reaction is a measure of how fast the reactants are being used up and how fast the products are being made. Reactions in which a gas is produced can be used to monitor the rate.