Which of the following factors does NOT affect reaction rate in an aqueous solution?

The factor that does not affect the reaction rate in an aqueous solution is the color of reactants.

The rate of a chemical reaction is influenced by several key factors such as the concentration of reactants, the presence of catalysts, and the surface area of solid reactants. Concentration plays a crucial role because a higher concentration of reactants generally increases the likelihood of collisions between particles, which can lead to a faster reaction. Catalysts speed up reactions by providing an alternative pathway with a lower activation energy, enhancing the reaction rate without being consumed in the process. The surface area of solid reactants is important as well, because smaller particles have a larger surface area that can interact with the liquid, increasing the opportunities for reaction.

Color, however, is simply a physical property of a substance that does not directly influence how reactants interact at the molecular level. While the color can sometimes indicate changes in a reaction or the presence of certain products, it does not directly affect the kinetics of the reaction or the frequency of effective collisions that lead to a chemical change. Therefore, color does not play a role in determining how quickly a reaction occurs in an aqueous solution.