How does the concentration of reactants affect the rate of a reaction?

A. Increasing the concentration increases the kinetic energy of the

molecules.

B. Increasing the concentration increases the molecules' collision

frequency

c. Increasing the concentration decreases the reaction's activation

energy

D. Increasing the concentration increases the temperature of the

solution

Answer: The amount of reactant doesn't really affect the rate of reaction, but the concentration does.

In order for there to be a reaction there has to be collisions between molecules, but only a fraction of these collisions are successful. The molecules have to be moving with enough energy, called the activation energy, to break the bonds between atoms. If there is a higher concentration of a solution, there are more molecules present per unit volume. This means that there will be more collisions and therefore more successful collisions, increasing the rate of reaction.

Explanation:

B