Home
Class 12
CHEMISTRY
The vapour pressure of a solvent decreas...

The vapour pressure of a solvent decreased by 10 mm of Hg when a non-volatile solute was added to the solvent. The mole fraction of solute in solution is 0.2, what would be the mole fraction of solvent if the decrease in vapour pressure is 20 mm of Hg?

A

`0.8`

B

`0.6`

C

`0.4`

D

`0.3`

Text Solution

Verified by Experts

The correct Answer is:
B

This question is based on Raoult’s law. It represent that the partial pressure of each component in the solution is directly proportional to its mole fraction for a solution i.e., `P _(A) prop X _(A) and p _(B) prop X _(B).`
From Aaoult.s law
`p ^(@) - p _(s) = p ^(@) xx `Mole fraction of solute
`10 = p ^(@) xx 0.2 `
`20 = p ^(@) xx X _(2)`
`therefore X _(2) = 0.4`
and `X _(1) = 1 - 0.4 = 0.6`
`X _(1) =` mole fraction of solvent
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • QUESTION-PAPERS-2012

    BITSAT GUIDE|Exercise Chemistry (Single correct answer type:)|40 Videos
  • QUESTION-PAPERS-2014

    BITSAT GUIDE|Exercise CHEMISTRY|40 Videos

Similar Questions

Explore conceptually related problems

How is the vapour pressure of a solvent affected when a non volatile solute is dissolved in it?

How is vapour pressure of a solvent affected when a non-volatile solute is dissolved in it ?

Knowledge Check

  • The vapour pressure of a solvent decreased by 10 mm of Hg when a non-volatile solute was added to the solvent. The mole fraction of solute is 0.2 , what would be the mole fraction of solvent if the decrease in vapour pressure is 20 mm of Hg .

    A
    0.8
    B
    0.6
    C
    0.4
    D
    0.2
  • The vapour pressure of a solvent decreased by 10 mmHg when a nonvolatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if the decrease in the vapour pressure is to be 20 mmHg?

    A
    0.8
    B
    0.6
    C
    0.4
    D
    0.2
  • The vapour pressure of a solvent decreases by 10 mm of mercury when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction or the solvent if the decrease in vapour presssure is to be 20 mm of mercury?

    A
    0.8
    B
    0.6
    C
    0.4
    D
    0.4
  • Similar Questions

    Explore conceptually related problems

    The vapour pressure of a solvent decreased by 10mm of mercury, when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraciton of the solvent, if decrease in the vapour pressure is to be 20 mm of mercury

    The vapour pressure of a liquid decreases by 10 torr when a non-volatile solute is dissolved. The mole fraction of the solute in solution is 0.1. What would be the mole fraction of the liquid if the decrease in vapour pressure is 20 torr, the same solute being dissolved?

    The vapour pressure of a liquid decreases by 10 torr when a non-volatile solute is dissolved. The mole fraction of the solute in solution is 0.1. What would be the mole fraction of the liquid if the decrease in vapour pressure is 20 torr, the same solute being dissolved?

    The vapour pressure of a solvent decreases by 5.4 torr when a non-volatile solute is added. In this solution, mole fraction of solute is 0.2. What would be mole fraction of the solvent if decreases in vapour pressure is 16.2 torr ?

    The mole fraction of a solvent in a solution is 0.8 . The mole fraction of the solute will be _____.