Effect of temperature on rate

The rate of a chemical reaction can be changed by altering the temperature. If the temperature is increased:

  • the reactant particles move more quickly
  • they have more energy
  • the particles collide successfully more often
  • the rate of reaction increases
  • [higher tier only] this is due to more particles having energy greater than or equal to the activation energy
Graph of total mass of product against time from start of reaction, for high and low temperatures.

Compared to a reaction at a low temperature, the graph line for the same reaction but at a higher temperature:

  • has a steeper gradient at the start
  • becomes horizontal sooner

This shows that the rate of reaction was greater at the higher temperature.