Which of the following will, in general, increase the rate of a chemical reaction?

• A. Adding an inert gas at constant volume
• B. Lowering the surface area of a solid reactant
• C. Decreasing the temperature
• D. Increasing the concentration of reactants

Answer: (D)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on factors such as concentration, temperature, surface area, and pressure.
2. Recognize that increasing the concentration of reactants generally increases the frequency of collisions between reactant molecules, thus increasing the reaction rate.
3. Note that adding an inert gas at constant volume does not change the concentration of reactants, so it typically does not affect the reaction rate.
4. Understand that lowering the surface area of a solid reactant decreases the available area for collisions, which usually decreases the reaction rate.
5. Know that decreasing the temperature reduces the kinetic energy of molecules, leading to fewer effective collisions and a slower reaction rate.