AIIMS 2006
- Exam
- AIIMS
- Year
- 2006
- Subject
- Chemistry
- Chapter
- Solutions
AIIMS 2006 · Chemistry · Solutions
Assertion : The water pouch of instant cold pack for treating...
Assertion : The water pouch of instant cold pack for treating athletic injuries breaks when squeezed and dissolves lowering the temperature.
Reason : Addition of non-volatile solute into solvent results into depression of freezing point of solvent.
Options
- AIf both assertion and reason are true and reason is the correct explanation of the assertion
- BIf both assertion and reason are true but reason is not the correct explanation of the assertion
- CIf assertion is true, but reason is false
- DBoth assertion and reason are false statements.
Correct answer
A. If both assertion and reason are true and reason is the correct explanation of the assertion
Step-by-step solution
Freezing point of a substance is defined as the temperature at which the vapour pressure of its liquid is equal to the vapour pressure of the corresponding solid. Since the addition of a non-volatile solute always lowers the vapour pressure of solvent, therefore it will be in equilibrium with solid phase at a lower pressure and hence at a lower temperature.