For the reaction 2A ⇌ B + C, KC = 4 x 10^-3. At a given time, the composition of reaction mixture is

Question

For the reaction \(2A \rightleftharpoons B + C ,K_C = 4 \times 10 ^{-3}.\) At a given time, the composition of reaction mixture is: [A] = [B] = [C] = 2 \(\times 10 ^{-3}\) M. Then, which of the following is correct? 

(1) Reaction is at equilibrium. 

(2) Reaction has a tendency to go in forward direction. 

(3) Reaction has a tendency to go in backward direction.

(4) Reaction has gone to completion in forward direction.

Answer 1

Correct option is (3) Reaction has a tendency to go in backward direction.

\(2A \rightleftharpoons B + C , K_C = 4 \times 10 ^{-3}\)

At a given time t, \(Q_C\) is to be calculated and been compared with \(K_C\).

\(Q_C = \frac {[B][C]}{[A]^2} = \frac {(2 \times 10 ^{-3})(2 \times 10 ^{-3})}{(2\times 10 ^{-3})^2}\)

\(Q_C = 1\)

As \(Q_C > K_C\), so reaction has a tendency to move backward.