Air containing 20.0mole% water vapor at an initial pressure of 1 atm absolute is cooled in a 1-l sealed vessel from 200°c to 15°c. a)what is the pressure in the vessel at the end of the process? (hint: the partial pressure of air in the system can be determined from the expression pair = nairrt/v.) b)what is the mole fraction of water in the gas phase at the end of the process? c)how much water (grams) is condensed?