2. One kg of saturated steam at 100°C and 1.01325 bar is contained in a rigid walled vessel. It lias a volume of 1.673 m3. It cools to 98°C ; the saturation pressure is 0.943 bar ; one kg of water vapour under these conditions has a volume of 1.789 m3. The amount of water vapour condensed (in kg) is