CuSO 4 ⋅ 5H2O(s) ⇌ CuSO4 ⋅ 3H2O(s) + 2H2O(g); Kp = 4×10^−4 atm^2 if the vapour pressure of water is 38 torr then percentage of relative humidity is: ( Assume all data at constant temperature)