# Rates and temperature

The greater the of , the greater the rate of reaction. If the of the reaction mixture is increased:

• move more quickly
• the of the particles increases
• the frequency of successful collisions between reactant particles increases
• the proportion of collisions which are successful increases
• the rate of reaction increases
Question

Explain what is meant by a 'successful' collision.

A collision between reactant particles with enough energy (the activation energy or more than the activation energy) to produce a reaction.

## Graphs

The rates of two or more reactions can be compared using a graph of or of formed against time. The graph shows this for two reactions.

Comparing two reactions - the higher the temperature, the greater the rate of reaction

The of the line is equal to the rate of reaction. The faster reaction at the higher temperature:

• gives a steeper line
• finishes sooner
The effect of temperature on the rate of reaction is due to two factors: frequency of collisions and energy of collisions. The increase in energy is usually the more important factor.