Question

In the reaction $N_2{O}_4\leftrightharpoons 2N{O}_2$ the degree of dissociation of $N_2{O}_4$ was found to be 0.4 when the reaction is conducted in a 2 litre vessel. The equilibrium constant $K_c$ of the reaction is:

• A. $0.53$
• B. $1.06$
• C. $0.265$
• D. $2$

Answer 1

The correct option is A $0.53$

$N_2{O}_4$ $\rightleftharpoons$ $2N{O}_2$

At t=0 : a o

At equilibrium : $a(1-\alpha )$ $2a\alpha$

But $\alpha =0.4$

$K_c=\frac{(2a\alpha {)}^2}{a(1-\alpha )}=\frac{4a^2{\alpha }^2}{a(1-\alpha )}$

=$\frac{4\times \frac{1}{2}\times (0.4{)}^2}{(1-0.4)}$

$K_c=0.53$