Q. If CuSO4.5H2O(s) 2381_equal.JPG CuSO4.3H2O(s) 2H2O(l) Kp = 1.086 × 0 10–4 atm2 at 25°C. The efflorescent nature of CuSO4.5H2O can be noticed when vapour pressure of H2O in atmosphere is?

1. > 7.29 mm
2. > 7.92 mm
3. < 7.92 mm
4. None