Question

question 10 of 10
how does temperature affect the rate of a reaction?
a. increasing the temperature decreases the potential energy of the reactants.
b. increasing the temperature gives the molecules more kinetic energy.
c. increasing the temperature lowers the activation energy of the reaction.
d. increasing the temperature increases the concentration of the reactants

Explanation:

• Temperature affects reaction rate. Kinetic energy of molecules is related to temperature.
• Option A: Temperature doesn't directly decrease potential energy of reactants in this context.
• Option B: According to kinetic - molecular theory, higher temperature means higher average kinetic energy of molecules. Molecules move faster, collide more frequently and with more energy (more likely to overcome activation energy), increasing reaction rate.
• Option C: Activation energy is a property of the reaction (determined by the nature of reactants and the reaction mechanism), not lowered by temperature. Catalysts lower activation energy.
• Option D: Temperature change doesn't increase reactant concentration (unless there is a phase change, but that's not the general case here). Concentration is about the amount of substance per unit volume.

Answer:

B. Increasing the temperature gives the molecules more kinetic energy.