Question

For the reaction $H_2\left(g\right)+I_2\left(g\right)\rightleftharpoons 2HI\left(g\right),K_c=47.6$, If the initial number of moles of each reactant and product is 1 mole, then in equilibrium:

• A. $\left[I_2\right]=\left[H_2\right];\left[I_2\right]>\left[HI\right]$
• B. $\left[I_2\right]<\left[H_2\right];\left[I_2\right]=\left[HI\right]$
• C. $\left[I_2\right]=\left[H_2\right];\left[I_2\right]<\left[HI\right]$
• D. $\left[I_2\right]>\left[H_2\right];\left[I_2\right]=\left[HI\right]$

Answer 1

The correct option is C $\left[I_2\right]=\left[H_2\right];\left[I_2\right]<\left[HI\right]$

$K_c=\frac{[HI{]}^2}{\left[H_2\right]\left[I_2\right]}$
$\left[H_2\right]=\left[I_2\right]$ will be same at equilibrium, since it is same at initial state.
$K_c=\frac{[HI{]}^2}{[I_2{]}^2}$
$K_c[I_2{]}^2=[HI{]}^2$
$47.6[I_2{]}^2=[HI{]}^2$
$\left[I_2\right]<\left[HI\right]$