Question

The equilibrium constant for the reaction $H_{2\left(g\right)}+I_{2\left(g\right)}\rightleftharpoons 2{HI}_{\left(g\right)}$ is $32$ at a given temperature.
The equilibrium concentration of $I_2$ and $HI$ are $0.5\times {10}^{-3}M$ and $8\times {10}^{-3}M$ respectively. The equilibrium concentration of $H_2$ is:

• A. $1\times {10}^{-3}M$
• B. $0.5\times {10}^{-3}M$
• C. $2\times {10}^{-3}M$
• D. $4\times {10}^{-3}M$

Answer 1

The correct option is D $4\times {10}^{-3}M$

eqlb constant $\left(k\right)=32$

$\left[I_2\right]=0.5\times {10}^{-3}M$

$\left[HI\right]=8\times {10}^{-3}M$

$H_2+I_2\rightleftharpoons RHI$

$K=\frac{[HI{]}^2}{\left[H_2\right]\left[I_2\right]}$

$32=\frac{{(8\times {10}^{-3})}^2}{(0.5\times {10}^{-3})\left[H_2\right]}$

$=⟩\left[H_2\right]=4\times {10}^{-3}M$

Hence, (D) is correct option