Choose the correct statements from the following regarding the reaction kinetics

(A) A catalyst does not affect the Gibbs energy of a reaction.
(B) A catalyst alters the equilibrium constant.
(C) For a zero order reaction, half life is dependent on the initial concentration of the reactant.
(D) Orientation of reactant molecules affects the reaction rate.

Choose the correct answer from the options given below:

(A), (C) and (D) only

The correct answer is Option (3) → (A), (C) and (D) only

(A) A catalyst does not affect the Gibbs energy of a reaction.
  A catalyst lowers the activation energy but does not change ΔG or equilibrium.

Thus, this statement is correct.

(B) A catalyst alters the equilibrium constant.
A catalyst increases the rate of both forward and backward reactions equally. Therefore, the equilibrium constant remains unchanged. Thus, this statement is incorrect.

(C) For a zero order reaction, half-life is dependent on the initial concentration of the reactant.
 For zero-order:

$t_{1/2} = \frac{[A]_0}{2k} \Rightarrow t_{1/2} \propto [A]_0$

Thus the half-life depends on the initial concentration. Therefore, this statement is correct.

(D) Orientation of reactant molecules affects the reaction rate.
According to collision theory, only collisions with proper orientation and sufficient energy lead to effective reactions. Thus, this statement is correct.

Hence, OPTION 3 -  (A), (C) and (D) only IS CORRECT