JEE Main 2022 Chemistry question
A gaseous mixture of two substances A and B, under a total pressure of 0.8 atm is in equilibrium with an ideal liquid solution. The mole fraction of substance A is 0.5 in the vapour phase and 0.2 in the liquid phase. The vapour pressure of pure liquid A is atm. (Nearest integer)
Answer: 2
Solution
The partial pressure of A is = = atm. By Raoult's law = °, so ° = 0.4/0.2 = 2 atm.