Question

For which reaction at $298K$, the value of $\frac{k_p}{k_c}$ is maximum and minimum respectively:
a) $N_2{O}_4\rightleftharpoons 2N{O}_2$
b) $2S{O}_2+O_2\rightleftharpoons 2S{O}_3$
c) $X+Y\rightleftharpoons 4Z$
d) $A+3B\rightleftharpoons 7C$

• A. d,c
• B. d,b
• C. c,b
• D. d,a

Answer 1

Answer: (B)

d,b

AT 298K, $\frac{K_P}{K_C}={\left(RT\right)}^{\Delta n}={(0.0821\times 298)}^{\Delta n}={\left(24.46\right)}^{\Delta n}$

Clearly $\Delta n$ is maximum $\Rightarrow K_P/K_C$ is maximum similarly minimum.

(a) $\Delta n=2-1=1$

(b) $\Delta n=2-1-2=-1$

(c) $\Delta n=4-2=2$

(d) $\Delta n=7-1-3=3$

Clearly (d) has maximum & (b) has minimum.