Which of the following would NOT increase the rate of a chemical reaction?

• A. Increasing the surface area of a solid reactant
• B. Decreasing the temperature
• C. Adding a catalyst
• D. Increasing the concentration of reactants

Answer: (B)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on factors that increase the frequency and energy of collisions between reactant molecules.
2. Recognize that increasing the surface area of a solid reactant exposes more particles to react, thus increasing the reaction rate.
3. Know that adding a catalyst provides an alternative reaction pathway with a lower activation energy, which increases the reaction rate without being consumed.
4. Recall that increasing the concentration of reactants raises the number of particles in a given volume, leading to more frequent collisions and a faster reaction rate.
5. Understand that decreasing the temperature reduces the kinetic energy of molecules, resulting in fewer collisions with sufficient energy to overcome the activation barrier, thus decreasing the reaction rate.