The independent variable I have chosen to investigate is temperature. I will see how the rate of the reaction is affected by a change in the temperature. My dependant variable is the time taken for the reaction to occur. The dependant variable will change when the independent variable changes. I will keep the concentrations of the sodium thiosulphate and hydrochloric acid the same throughout the experiment to ensure that it is a fair test.

Prediction

I predict that when I increase the temperature of the sodium thiosulphate and hydrochloric acid, the rate of reaction will also increase. The reason for this is because increasing the temperature of a reactant increases the kinetic energy of the particles, therefore, they move faster. If the particles move faster, they are more likely to collide. The graph below is a prediction of what I expect to occur:

Preliminary Work

I am now...