Question

By the addition of a catalyst during a chemical reaction which of the following quantities will get altered?
A. Entropy
B. Internal energy
C. Enthalpy
D. Activation energy

Answer 1

Hint: We know that catalysts are those substances which alters the rate of reaction by changing the path of the reaction. Most of the time a catalyst is used to increase the rate of reaction. A catalyst can either be a solid, liquid or gaseous catalyst. The reactions which involve a catalyst in their reaction is known as Catalytic reaction.

Complete Answer:
- According to our question, the correct answer is activation energy as a catalyst is a substance that increases the rate of a chemical reaction without itself being used up. It remains unchanged chemically providing an alternate path for the reaction at an accelerated rate by lowering the activation energy. There are two types of catalyst namely positive and negative catalyst.
- Activation energy is defined as the minimum amount of extra energy which is required by a reacting molecule to convert a reacting molecule into a product. We can also say that it is the minimum amount of energy needed to activate molecules or atoms so that they can undergo a chemical reaction.
- Activation energy is denoted by ${E_a}$ and is measured in joules $(J)$ or kilojoules per mole $(KJ/mol)$

Therefore, the correct answer is Option D.

Note: The activation energy does not depend upon the temperature, pressure, volume, concentration or coefficients of the reactant. the positive catalyst will provide an alternative path in which the value of ${E_a}$ will be low, while the negative catalyst provides an alternative path in which the value of ${E_a}$ will be high.