How does increasing concentration affect the rate of a reaction?

How does increasing concentration affect the rate of a reaction?

• A. Has no effect
• B. Changes activation energy
• C. Increases collision frequency and rate
• D. Decreases collisions

Answer: (C)

Raising concentration increases the number of reacting particles in a given volume, so they collide more often. Since a reaction can only happen when particles collide with enough energy and the right orientation, more collisions per second generally speed up the rate of product formation. The activation energy is the energy barrier that must be overcome for the reaction to proceed, and changing concentration doesn’t alter that barrier; it only affects how often collisions occur. So the rate increases because collision frequency goes up. The exact change in rate with concentration depends on the reaction order, but the fundamental idea is that more particles lead to more collisions and a faster rate.

Raising concentration increases the number of reacting particles in a given volume, so they collide more often. Since a reaction can only happen when particles collide with enough energy and the right orientation, more collisions per second generally speed up the rate of product formation. The activation energy is the energy barrier that must be overcome for the reaction to proceed, and changing concentration doesn’t alter that barrier; it only affects how often collisions occur. So the rate increases because collision frequency goes up. The exact change in rate with concentration depends on the reaction order, but the fundamental idea is that more particles lead to more collisions and a faster rate.