Investigation Design Temperature and the Rate of Reaction
A teacher gave the following hypothesis to her class to investigate: ‘An increase in temperature of 10 °C will double the rate of a chemical reaction.’
Two students, Sandra and Breda, started to design an investigation to test this hypothesis.
The first thing that Sandra and Breda did was make a list of the factors they knew affected the rate of a reaction. This would help them to find out what factors they would change in their investigation and what factors they would need to keep the same to carry out a fair test.
1 What factors affect the rate of a chemical reaction?
After making their list, Sandra and Breda needed to select a reaction for this investigation. They chose the reaction between sodium thiosulfate and hydrochloric acid because the reaction produces an insoluble solid (sulfur). They decided to time how quickly the solution went cloudy at different temperatures.
Sandra drew the following diagram of the investigation set-up in her laboratory copy:
