A mixture of 2.0 mol of ${{\text{H}}_{\text{2}}}$ and 2.0 mol of ${{\text{I}}_{\text{2}}}$ is allowed to reach equilibrium in the gaseous state at a certain temperature in a ${\text{1.0 d}}{{\text{m}}^{\text{3}}}$ flask. At equilibrium, 3.0 mol of HI are present. What is the value of ${K_{\text{c}}}$ for this reaction?

$${{\text{H}}_{\text{2}}}{\text{(g)}} + {{\text{I}}_{\text{2}}}{\text{(g)}} \rightleftharpoons {\text{2HI(g)}}$$

A.     ${K_{\text{c}}} = \frac{{{{(3.0)}^2}}}{{{{(0.5)}^2}}}$

B.     ${K_{\text{c}}} = \frac{{3.0}}{{{{(0.5)}^2}}}$

C.     ${K_{\text{c}}} = \frac{{{{(3.0)}^2}}}{{{{(2.0)}^2}}}$

D.     ${K_{\text{c}}} = \frac{{{{(0.5)}^2}}}{{{{(3.0)}^2}}}$

A