Read the Assertion and Reason below and choose the correct option. — Chemical Equilibrium Chemistry Question

💡 Solution & Explanation

The equilibrium constant is $K_c = b/a$. Upon adding 5 moles of A and 3 moles of B, the reaction quotient becomes $Q_c = (b+3)/(a+5)$. If $a$ is very large and $b$ is very small, $Q_c$ can be greater than $K_c$, meaning the reaction would move in the backward direction. Therefore, Statement I is incorrect because the reaction does not "must" move forward; it depends on the original values of 'a' and 'b'. Statement II correctly notes that the shift can be in any direction. Therefore, correct answer is D.