What happens to the rate of reaction when the concentration of solutions is increased?

When the concentration of reactants in a solution is increased, there are more reactant particles present in a given volume. This increased number of particles leads to a greater chance of collisions between them. According to collision theory, for a reaction to occur, reactant particles must collide with sufficient energy and proper orientation.

As the concentration increases, the frequency of these effective collisions rises, which in turn accelerates the rate of reaction. The more reactants there are in a solution, the more opportunities there are for them to interact, thus increasing the overall reaction rate. This relationship is often observed in various chemical reactions and supports the principle that greater concentrations lead to enhanced reactivity.

In scenarios where concentration is fixed or low, you would not see the same increase in reaction rate, which differentiates the correct choice from the others.