What is the effect of a catalyst lowering the activation energy of a chemical reaction?

• A. It increases the rate of the reaction.
• B. It increases the enthalpy change of the reaction.
• C. It makes the reaction non-spontaneous.
• D. It changes the equilibrium position of the reaction.

Answer: (A)

Verified step by step guidance

1. Understand that activation energy (E_a) is the minimum energy required for reactants to transform into products during a chemical reaction.
2. Recognize that a catalyst provides an alternative reaction pathway with a lower activation energy, which means more reactant molecules have enough energy to overcome this barrier at a given temperature.
3. Recall that lowering the activation energy does not affect the overall enthalpy change (\$\Delta H\$) of the reaction, because the catalyst does not alter the initial or final energy states of reactants and products.
4. Note that a catalyst does not change the spontaneity of the reaction, which depends on the Gibbs free energy change (\$\Delta G\$), nor does it shift the equilibrium position, which is determined by the relative energies of reactants and products.
5. Conclude that by lowering the activation energy, the catalyst increases the rate at which the reaction reaches equilibrium, meaning the reaction proceeds faster.