Question

The equilibrium constant for the reaction $H_{2\left(g\right)}{I}_{2\left(g\right)}\leftrightharpoons 2H{I}_{\left(g\right)}$ is a 2 at a certain temp. The equilibrium concentrations of $H_2$ and $HI$ are $2mole.li{t}^{-1}$. What is the equilibrium concentration $($in mole .lit${}^1)$ of $I_2$?

• A. $16$
• B. $4$
• C. $8$
• D. $1$

Answer 1

Answer: (D)

$1$

The given reaction is:

${H_2}_{\left(g\right)}+{I_2}_{\left(g\right)}⟶2H{I}_{\left(g\right)}$

Equilibrium constant for reaction= $2$ (given)

Equilibrium constant for $H_2=2$ mole/lit

Equilibrium constant for $HI=2$ mole/lit

Equilibrium constant=$\frac{{\text{(Equilibrium constant of HI)}}^2}{\text{(E.C of}{H}_2\left)\text{(E.C of}{I}_2\right)}$

$E.C$ of $I_2=\frac{{\text{(E.C of HI)}}^2}{\text{(E.C of}{H}_2)\text{(E.C of Reaction)}}$

$=\frac{(2{)}^2}{2\times 2}$

$E.C$ of $I_2=1$ mole/lit