KCET 2009 Chemistry Solved Paper

Question : 42 of 60

Marks: +1, -0

Vapour pressure of pure ' A ' is 70‌mm of Hg at 25∘C. It forms an ideal solution with ' B ' in which mole fraction of A is 0.8 . If the vapour pressure of the solution is 84‌mm of Hg at 25∘C, the vapour pressure of pure ' B ' at 25∘C is