Question

In the given reaction : $A + 2B \rightleftharpoons 2C$ moles each of $A$ and $B$ present in $10\, L$ of solution combine to form $1$ mole of $C$. Calculate $K_c$ for the reaction.

• A. 1.5
• B. 6.67
• C. 0.15
• D. 2.3

Answer 1

Answer: (B)

As $1$ mole of $C$ is formed at equilibrium,
$2x = 1 \Rightarrow x = 0.5$
$\Rightarrow$ Equilibrium concentration of $A = 1.5/10$
$B = 1/10$ and $C = 1/10$
$K_{c}=\frac{\left[C\right]^{2}}{\left[A\right]\left[B\right]^{2}}=\frac{\left[1/10\right]^{2}}{\left[1.5 / 10\right]\left[1 / 10\right]^{2}}=6.67$