Question

If $1.0$ mole of $I_{2}$ is introduced into $1.0$ litre flask at $1000\, K$, at equilibrium $\left(K_{c}=10^{-6}\right)$, which one is correct?

• A. $\left[ I _{2}( g )\right]>\left[ I ^{-}( g )\right]$
• B. $\left[ I _{2}( g )\right]<\left[ I ^{-}( g )\right]$
• C. $\left[ I _{2}( g )\right]=\left[ I ^{-}( g )\right]$
• D. $\left[ I _{2}( g )\right]=\frac{1}{2}\left[ I ^{-}( g )\right]$

Answer 1

Answer: (A)

$\ce{ $\underset{\text{ 1 -x}}{\ce{I_{2} }}$ <=> $\underset{\text{ 2x }}{\ce{ 2 I^{-} }}$ }$
$K_c = \frac{(2x)^2}{(1-x)} = 10^{-6}$
It shows that (1 - x) < 2x