NEET2021ChemistrySolutionsActual
The correct option for the value of vapour pressure of a solution at 45 º C with benzene to octane in molar ratio 3   :   2 is: [At 45 ° C vapour pressure of benzene is 280   mm   Hg and that of octane is 420   mm   Hg . Assume Ideal gas]
Options
- A160   mm of Hg
- B168   mm of Hg
- C336   mm of Hg
- D350   mm of Hg
Correct answer
C. 336   mm of Hg
Step-by-step solution
Given: P B ° = 280   mm of Hg ,   P o ° = 420   mm of Hg X B = 3 5 and X o = 2 5 We know that according to Raoult's Law P T = X B P B ° + X o P o ° = 3 5 × 280 + 2 5 × 420 = 336   mm of Hg