Which factor does not affect the rate of a reaction?

Which factor does not affect the rate of a reaction?

• A. Color of the substances
• B. Surface area
• C. Temperature
• D. Concentration

Answer: (A)

The rate of a reaction depends on how often particles collide and how energetically those collisions occur. Temperature increases kinetic energy, so particles collide more forcefully and frequently; this boosts the rate. Increasing concentration raises how many particles are available to collide, also speeding up the rate. Increasing surface area for a solid reactant provides more places where collisions can happen, again accelerating the reaction. The color of the substances doesn’t change how often collisions happen or how energetic they are, so it doesn’t affect the rate. Therefore, color is the factor that does not affect the rate.

The rate of a reaction depends on how often particles collide and how energetically those collisions occur. Temperature increases kinetic energy, so particles collide more forcefully and frequently; this boosts the rate. Increasing concentration raises how many particles are available to collide, also speeding up the rate. Increasing surface area for a solid reactant provides more places where collisions can happen, again accelerating the reaction. The color of the substances doesn’t change how often collisions happen or how energetic they are, so it doesn’t affect the rate. Therefore, color is the factor that does not affect the rate.