NTA Abhyas JEE Main2020ChemistrySolutionsPractice
Mole fraction of the toluene in the vapour phase which is in equilibrium with a solution of benzene p o = 120 T o r r and toluene p o = 80 T o r r having 2.0 moles of each, is
Options
- A0.50
- B0.25
- C0.60
- D0.40
Correct answer
D. 0.40
Step-by-step solution
Mole fraction of toluene vapour = p T o X T P T o X T + p B o X B X T = Mole fraction of toluene in solution =2/4 = 0.5 X B = Mole fraction of benzene = 2/4 = 0.5 p T o = Vapour pressure of pure toluene = 80 mm p T o = Vapour pressure of benzene = 120 mm = 80 × 4 5 . 80 + 120 × 0 . 5 = 0.40