Question

At certain temperature, 50% of HI is dissociated into $H_2$ and $I_2$, the equilibrium constant is

• A. 1
• B. 3
• C. 0.5
• D. 0.25

Answer 1

Answer: (D)

0.25

Answer 2

$2HI \to H_{2}+I_{2}$
$\begin{matrix}Initial\, moles&1&-&-\\\ E moles&1-0.5&0.25&0.25\end{matrix}$
$K=\frac{0.25\times0.25}{(0.5)^{2}}$