The rate of a chemical reaction increases with temperature primarily because:

• A. Reactants become more soluble.
• B. More particles have enough energy to overcome activation energy.
• C. The products convert back to reactants.
• D. The reaction forms fewer molecules.

Answer: (B)

Temperature affects how energy is distributed among reacting molecules. When it gets hotter, more molecules have enough energy to get over the activation energy barrier in a collision. That means a higher fraction of collisions are effective, so the reaction proceeds faster. This idea is captured by the Arrhenius relationship, where the rate constant increases as temperature rises because the exponential term becomes larger when Ea/RT decreases.

Solubility changes can influence how well reactants mix, but they aren’t the main reason temperature speeds up a reaction. The notion that products simply revert to reactants at higher temperature relates to equilibrium, not the rate itself. And heating doesn’t inherently reduce the number of molecules formed; it changes how many successful collisions occur, not the overall count of product molecules produced.