Question

What is the effect of a catalyst on the activation energy and enthalpy of a reaction?

Hint:

{Catalyst:} Lowers \(E_a\) (faster reaction) No change in \(\Delta H\) (same energy difference).

Answer 1

Concept: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It provides an alternative reaction pathway with different energy requirements. Effect on Activation Energy:

• A catalyst lowers the activation energy (\(E_a\)) of a reaction.
• It provides an alternative pathway with a lower energy barrier.
• As a result, more reactant molecules acquire sufficient energy to undergo reaction, increasing the reaction rate.

Effect on Enthalpy Change (\(\Delta H\)):

• A catalyst does not change the enthalpy change of the reaction.
• The initial and final energy states of reactants and products remain the same.
• Since \(\Delta H\) depends only on these energy states, it remains unaffected.

Conclusion: Thus, a catalyst speeds up a reaction by lowering activation energy but does not alter the enthalpy change or thermodynamics of the reaction.