Question

For the reaction
$2A+B\rightleftharpoons 3C$ at $298K$, $K_c=49$
A $3L$ vessel contains $2,1$ and $3$ moles of $A,B$ and $C$ respectively. The reaction at the same temperature:

• A. must proceed in forward direction
• B. must proceed in backward direction
• C. must be in equilibrium
• D. cannot be predicted

Answer 1

The correct option is A must proceed in forward direction

For the reaction
$2A+B\rightleftharpoons 3C$ at $298K$, $K_c=49$
A $3L$ vessel contains $2,1$ and $3$ moles of $A,B$ and $C$ respectively. The reaction at the same temperature must proceed in forward direction.
$Q_c=\frac{[C{]}^3}{\left[A{]}^2\right[B]}$
$Q_c=\frac{(\frac{\text{3 mol}}{\text{3 L}}{)}^3}{(\frac{\text{2 mol}}{\text{3 L}}{)}^2\times (\frac{\text{1 mol}}{\text{3 L}})}$
$Q_c=6.75$
But $K_c=49$
$Q_c<K_c$
The product concentration is less than equilibrium value.
The reactant concentration is more than the equilibrium value.