Rate of reaction is a measure of how quickly a reaction occurs - what is measured is the change in amount of either reactant or product per second.
Rate of reaction is explained by collision theory. Reactants must collide with enough energy before they will react. Collisions with enough energy are known as "successful collsions". The more successful collisions per second, the faster the rate.
Explain how the four main factors affect rate of reaction.
You will need to: state what each factor is; say how if affects rate; and explain how this happens.
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