Activation energy is the minimum amount of energy required for a chemical reaction to take place. This means that particles need to have energy greater than or equal to the activation energy for a successful collision to occur.
Increasing the temperature increases the energy of the reacting particles. As these particles gain more energy, they will move faster, which increases the frequency of collisions. So, increasing the temperature increases the frequency of collisions.
Also, each collision now has more energy. This allows more particles to overcome the activation energy barrier, which leads to more successful collisions.
We can represent the effect of temperature on reaction rate using a rate of reaction graph.
The graph line for the higher temperature shows a higher rate of reaction than the line for the lower temperature. We know this because the graph line for the higher temperature has a steeper gradient and it becomes horizontal faster.