AIIMS 201827 May
- Exam
- AIIMS
- Year
- 2018
- Date
- 27 May
- Subject
- Chemistry
- Chapter
- Solutions
AIIMS 2018 · 27 May · Chemistry · Solutions
Assertion : The vapour pressure of a liquid decreases if some non...
Assertion : The vapour pressure of a liquid decreases if some non volatile solute is dissolved in it.
Reason : The relative lowering of vapour pressure of a solution containing a nonvolatile solute is equal to the mole fraction of the solute in the solution.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
Step-by-step solution
On adding a non volatile solute in a liquid the vapour pressure decreases because some molecules of the solvent on the surface are replaced by the molecules of the solute.