Question

MATCH THE COLUMN :

Column I	Column II
(A) Kp < Kc PSR	(P) $N_2 + 3H_2 \rightleftharpoons 2NH_3$
(B) Introduction of inert gas at constant pressure will decrease the concentration of reactants Q	(Q) $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$
(C) $K^\circ p$ is dimensionless R	(R) $2NO_2 (g) \rightleftharpoons N_2O_4 (g)$
(D) Temperature increase will shift the reaction on product side. P	(S) $NH_3 (g) + HI (g) \rightleftharpoons NH_4I (s)$

• A. (A) $\rightarrow$ (P), (B) $\rightarrow$ (S), (C) $\rightarrow$ (R), (D) $\rightarrow$ (Q)
• B. (A) $\rightarrow$ (S), (B) $\rightarrow$ (P), (C) $\rightarrow$ (Q), (D) $\rightarrow$ (R)
• C. (A) $\rightarrow$ (R), (B) $\rightarrow$ (Q), (C) $\rightarrow$ (S), (D) $\rightarrow$ (P)
• D. (A) $\rightarrow$ (Q), (B) $\rightarrow$ (R), (C) $\rightarrow$ (P), (D) $\rightarrow$ (S)

Answer 1

Answer: (A)

(A) $\rightarrow$ (P), (B) $\rightarrow$ (S), (C) $\rightarrow$ (R), (D) $\rightarrow$ (Q)

Answer 2

• (A) $K_p < K_c$: This condition is met when $\Delta n_g < 0$. Reaction (P) $N_2 + 3H_2 \rightleftharpoons 2NH_3$ has $\Delta n_g = 2 - (1+3) = -2$, satisfying the condition.
• (B) Introduction of inert gas at constant pressure: This increases the volume, decreasing partial pressures and concentrations of all gaseous species. Reaction (S) $NH_3(g) + HI(g) \rightleftharpoons NH_4I(s)$ has gaseous reactants whose concentrations decrease.
• (C) $K^\circ_p$ is dimensionless: The thermodynamic equilibrium constant $K^\circ_p$ is defined using activities or partial pressures relative to a standard state, making it dimensionless. Reaction (R) $2NO_2(g) \rightleftharpoons N_2O_4(g)$ is a standard example for this concept.
• (D) Temperature increase will shift the reaction on product side: This indicates an endothermic forward reaction ($\Delta H > 0$). Reaction (Q) $PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$ is endothermic; hence, increasing temperature favors product formation.