Water is placed in a test tube and kept in dry air at 298 K and 1 atm. The distance between the upper edge of the test tube and the surface of the water is 5 cm and cross-sectional area of the test tube is 2 cm2. Density of water is 1000 kg/m3 and density of water vapour is 1.2 kg/m3.

3.1 Calculate the rate of evaporation of the water.

3.2 Determine t he rate of decrease of water surface per day.