Question

The role of a catalyst is to change _____________ .

• A. Gibbs energy of reaction
• B. enthalpy of reaction
• C. activation energy of reaction
• D. equilibrium constant

Hint:

When a graph is plotted between energy vs time of a reaction, the peak most often is in the center of the graph. This peak is indicative of the maximum energy the reactant reaches when its conversion to product occurs.  After the peak point, the energy reduces. This is the point where the catalysts have an important role to play.

Answer 1

The Correct Option is C

A catalyst modifies the activation energy of a reaction.

It achieves this by altering the activation energy, either increasing or decreasing it. A catalyst accelerates a reaction without being consumed. Therefore, catalysts can alter the reaction pathway. There are two classifications: positive and negative catalysts. By influencing the activation energy, catalysts enable molecules to react, thereby accelerating the reaction and enhancing efficiency. This acceleration is typically accomplished by lowering the activation energy.

• Positive catalysts expedite reactions by reducing activation energy.
• Negative catalysts decelerate reactions by increasing activation energy.

Also Read: Chemical Kinetics