A student investigates how temperature affects the rate of reaction between two colourless solutions containing ions.
When she mixes the solutions, a reaction takes place and after a while the mixture suddenly turns blue. She performs the experiment at five different temperatures and on each occasion she measures the time taken for the mixture to turn blue.
The table shows her results:
| Temperature in ∘C^\circ\text{C}∘C | 16 | 22 | 30 | 44 | 60 |
|---|---|---|---|---|---|
| Time taken in seconds | 180 | 148 | 120 | 92 | 80 |
Describe the relationship shown by the results between temperature and the time taken for the mixture to turn blue.
Estimate the time taken for the mixture to turn blue at 38 ∘C38\ ^\circ\text{C}38 ∘C.
Explain, in terms of particles, why an increase in temperature increases the rate of this reaction.
State one variable that must be kept constant for the experiment to be valid (a fair test).
