Which statement explains why the speed of some chemical reactions is increased when the surface area of the reactant is increased?
A. This change increases the concentration of the reactant.
B. This change increases the density of the reactant particles.
C. This change exposes more reactant particles to a possible collision.
D. This change alters the electrical conductivity of the reactant particles.
Reaction rate is affected by nature and concentration of reactants, temperature, surface area and a catalyst. Increasing surface area exposes more particles to contact with reactants, increasing the number of particle collisions. Imagine a cube of chocolate 3 feet by 4 feet and 2 inches thick. Take the same block and make it into a 24 candy bars. A class of chemistry students could eat the bars faster than the single chocolate block.