According to collision theory, what effect does increasing the concentration of reactants have?

Increasing the concentration of reactants results in a greater number of reactant particles within a given volume. According to collision theory, reaction rates are dependent on how frequently the reactant particles collide with one another. When the concentration of these particles increases, the probability of successful collisions—collisions that occur with the correct orientation and sufficient energy to overcome the activation barrier—increases as well.

As a consequence, this heightened frequency of effective collisions leads to an increased rate of reaction. Essentially, more particles in the same space means that they are more likely to encounter one another, resulting in more reactions occurring per unit of time. Therefore, the correct understanding of the effect of increasing reactant concentration aligns with the assertion that it increases the frequency of collisions and thus increases the rate of reaction.