question_answer 9)

Vapour pressure of pure water at 298 K is 23.8 mm Hg. 50 g of urea (NH2CONH2) is dissolved in 850 g of water. Calculate the vapour pressure of water for this solution and its relative lowering.

Answer:

Step 1. To calculate vapour pressure of water for the solution Here, p° = 23.8 mm. w2 = 50 g, M2 (urea) = 60 g mol-1               w2 = 850 g, M1(water) = 18 g mol-1             = 23.4 mm Hg Step II. To calculate RLVP