At equilibrium the concentration of water in vapour phase (C<sup>*</sup>) in kg/m<sup>3</sup> of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C<sup>*</sup> = 0.0667 m. To maintain dry conditions in a room of air space 100 m<sup>3</sup> containing 2.2 kg of water vapour initially, 10 kg of dry silica gel is kept in the room. The fraction of initial water remaining in the air space after a long time (during which the temperature is maintained constant) is

Correct Answer: 0.4