NTA Abhyas JEE Main2020ChemistrySolutionsPractice
The vapour pressure of pure liquid A is 10 torr and at the same temperature when 9 g of B solid dissolved in 20 g of A, its Vapour pressure is reduced to 5 torr . If the molecular mass of A is 200 amu, then the molecular mass of B is
Options
- A100 amu
- B90 amu
- C75 amu
- D120 amu
Correct answer
B. 90 amu
Step-by-step solution
P 0 - P s P s = n N 10 - 5 5 = 9 × 200 M × 20 M   =   90   amu