Question

The chemical equilibrium of reversible reaction is not influenced by:
A. Pressure
B. Catalyst
C. Concentration of the reactants
D. Temperature

Answer 1

Hint: The chemical equilibrium defines a state in which the forward reaction's rate equates with the backward reaction's rate. In other words, at equilibrium, no changes take place in the reactant and product concentration with time.

Complete Step by Step Solution:
Let's discuss all the options one by one.
Now, we will discuss how pressure affects equilibrium. The change in volume causes the pressure change. There is the effect of pressure change on the gaseous reaction as the total count of reactants and products in the gaseous state are different. So, pressure affects the equilibrium.

Let's discuss how the temperature affects the equilibrium. For an exothermic reaction, the increase in temperature causes a decrease in the value of the equilibrium constant. And the increase of the equilibrium constant value occurs on the increasing temperature in an endothermic reaction. So, temperature affects the equilibrium.

Now, we will discuss how a catalyst affects equilibrium. The role of a catalyst is only to speed up a reaction. So, no change of number reactants and products in equilibrium occurs. It facilitates a reaction to take place through a lower activation energy transition state. Therefore, a catalyst possesses no effect on the equilibrium.
Hence, option B is right.

Note: At equilibrium, there are some properties and conditions of a system such as, the system needs to be a closed one, the rate of the forward and the reverse reaction is equal, and both the backward and forward reactions are taking place, etc.