Question

Given NaSO4.10H2O(s)⇌NaSO4(s)+10H2O(g);Kp=4.08×10−25 and vapour pressure of water at 0∘C = 4.58 Torr. At what relative humidity will Na2SO4 be deliquescent when exposed to the air at 0∘C ?

Answer 1

Deliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution. Deliquescence occurs when the vapour pressure of the solution that is formed is less than the partial pressure of water vapour in the air.