In the reaction between hydrochloric acid and sodium thiosulphate, a fine precipitate of sulphur slowly forms, to measure the rate of reaction, we time how long it takes to form the precipitate. Five of the most common ways to influence the rate of reaction can be explained using collision theory. They are: changing the nature of the reactants, changing the concentration of one or more of the reactants, changing the temperature at which a reaction is performed, changing the surface area of a solid reactant, adding a catalyst .

I have chosen to study how the rate of reaction changes when the temperature of the sodium thiosulphate is varied.

There is no available catalyst for the reaction between hydrochloric acid and sodium thiosulphate.

As both the reactants are liquids I cannot change the surface area of a reactant.

Throughout the experiment the concentration of the reactants is not...