Question

Which of the following is not a characteristic property of chemical equilibrium?

• A. Rate of forward reaction is equal to rate of backward reaction at equilibrium
• B. After reaching the chemical equilibrium, the concentration of reactants and product remain unchanged with time
• C. For $A\left(g\right)\rightleftharpoons B\left(g\right),K_c$ is ${10}^{-2}$. If this reaction is carried out in the presence of a catalyst, the value of $K_c$ decreases
• D. After reaching the equilibrium, both forward and backward reaction continue to take place

Answer 1

The correct option is C For $A\left(g\right)\rightleftharpoons B\left(g\right),K_c$ is ${10}^{-2}$. If this reaction is carried out in the presence of a catalyst, the value of $K_c$ decreases

On addition of a catalyst, the value of $K_c$ does not change for a reaction in equilibrium because catalyst speeds up the rate of forward and backward reaction to the same extent.

Also, other facts for a reaction in equilibrium are :
i) Rate of forward reaction is equal to the rate of backward reaction at equilibrium.
ii) After reaching the chemical equilibrium, the concentrations of reactants and products remain unchanged with time.
iii) After reaching the equilibrium, both forward and backward reaction continue to take place.