Question

an increase in temperature affects the reaction rate by
○ decreasing the velocities of particles that collide in the reaction.
○ increasing the number of molecules that have sufficient kinetic energy to react.
○ increasing the number of molecules that have sufficient potential energy to react.
○ decreasing the energy that particles need to overcome the energy activation barrier.

Explanation:

• Analyze Option 1: Increasing temperature increases particle velocities (kinetic energy), so this is wrong.
• Analyze Option 2: Higher temperature gives more molecules enough kinetic energy (activation energy related) to react, increasing reaction rate. This matches collision theory.
• Analyze Option 3: Reaction depends on kinetic (not potential) energy for overcoming activation energy, so this is incorrect.
• Analyze Option 4: Temperature doesn't change the activation energy (energy barrier); catalysts do. So this is wrong.

Answer:

B. increasing the number of molecules that have sufficient kinetic energy to react