A particular material has a latent heat of vaporization of 5×103 J/mole, constant along the coexistence curve. One mole of this material exists in two-phase (liquid--vapor) equilibrium in a container of volume V=10−2 m3, at a temperature of 300 K and a pressure of 105 Pa. The system is heated at constant volume, increasing the pressure to 2.0×105 Pa. (Note that this is not a small ΔP.) The vapor phase can be treated as a monatomic ideal gas, and the molar volume of the liquid can be neglected relative to that of the gas. Find the initial and final mole fractions of the vapor phase [x≡Ng/(Ng+Nℓ)].