Which of the following affects reaction rates?

The influence on reaction rates is primarily determined by factors that directly affect the frequency and energy of collisions between reactant molecules. The surface area, temperature, and concentration of reactants are crucial in this context.

When the surface area of reactants increases, such as when a solid is divided into smaller pieces or powders, more particles are exposed to react, leading to a higher likelihood of collisions. This increased collision frequency accelerates the reaction rate.

Temperature plays a significant role as well; higher temperatures provide reactant molecules with greater kinetic energy. An increase in kinetic energy results in more frequent and energetic collisions, which also enhances the likelihood of successful reactions occurring.

Concentration is another key factor—higher concentrations of reactants mean that more molecules are present in a given volume, leading to greater collision opportunities. This increased interaction between molecules raises the reaction rate significantly.

In contrast, the other options—such as the color of reactants, the size of the container, and the molecular shape of products—do not inherently influence the reaction rate in a direct manner. The color may indicate certain properties of the reactants but does not affect how quickly they react. The size of the container can impact the pressure and concentration of gaseous reactants, but it is not