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

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

Answer: (B)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on factors that increase the frequency or energy of collisions between reactant molecules.
2. Recall that increasing the temperature increases the kinetic energy of molecules, leading to more frequent and energetic collisions, thus increasing the reaction rate.
3. Recognize that adding a catalyst provides an alternative reaction pathway with a lower activation energy, which increases the reaction rate without being consumed.
4. Know that increasing the surface area of a solid reactant exposes more particles to react, increasing the frequency of collisions and thus the reaction rate.
5. Identify that decreasing the concentration of reactants reduces the number of particles available to collide, which decreases the reaction rate, so it will NOT increase the rate.