The rate of a reaction varies based on temperature, meaning for example, in one reaction, hotter temperatures may speed up the rate of reaction, whereas in the same reaction, colder temps may slow it down.
Increasing the temperature increases the rate of reaction because particles gain more kinetic energy. This means collisions are more frequent and because they have more kinetic energy collisions occur with more energy and therefore more collisions overcome the activation energy (the minimum amount of energy required for a collision to be successful).
