Which statement is correct for the equilibrium \({{\text{H}}_2}{\text{O(l)}} \rightleftharpoons {{\text{H}}_2}{\text{O(g)}}\) in a closed system at 100 °C?

A.     All the \({{\text{H}}_{\text{2}}}{\text{O(l)}}\) molecules have been converted to \({{\text{H}}_{\text{2}}}{\text{O(g)}}\).

B.     The rate of the forward reaction is greater than the rate of the reverse reaction.

C.     The rate of the forward reaction is less than the rate of the reverse reaction.

D.     The pressure remains constant.

D

One respondent stated that candidates had to assume that equilibrium has been established since the question does not make this clear. It was felt that this is clearly implied in the question by stating that the container was closed and at constant temperature.