The equilibrium constant Kp = (6.39x10^-2) for the following reaction in the gas phase at a given temperature T: H2O(g) + Cl2O(g) = 2 HOCl(g)

Calculate the pressure (in bar) of H2O(g) at equilibrium in the reaction vessel at temperature T if the initial pressures of H2O(g) and Cl2O(g) are both equal to (3.9x10^-1) bar.