Practise explaining rate changes with collision theory, linking particle energy, surface area, concentration and graph shape.
A student investigates the effect of temperature on the rate of reaction between two solutions, A and B . When the reaction occurs, the mixture turns from colourless to blue.
This is the student's method.
- pour 25 cm3 of solution A into a conical flask
- add solution B and measure the temperature of the mixture
- record the time taken for the mixture to turn blue
The student repeats this method at different temperatures.
Explain how increasing the temperature affects the rate of a reaction.
Refer to particle collision theory in your answer.
An explanation that links the following three points:
- rate of reaction increases
- mean kinetic energy of particles increases
- more successful collisions per second / per unit time / more frequent successful collisions
Allow:
- reaction is faster / speeds up
- particles move faster
- more frequent collisions having energy >= activation energy
Ignore:
- vibrate more / faster