a capillary tube is partially filled with liquid water at 40 evacuated to remove all aie and sealed after which the liquid fills 20% of the tube by volume. the tube is then gradually heated until a temperature is reached for which the vapor liquid interface in the tube disappears. use the information from the steam tables and your understanding of the PV behavior of pure fluids to estimate the pressure at which the interface disappears from the tube. At that point, is the phase a liquid of vapor?