Question

Assertion: Greater the value of van der Waals constant ‘a’ greater is the liquefaction of gas.
Reason: ‘a’ indirectly measures the magnitude of attractive forces between the molecules.

<!--td {border: 1px solid #cccccc;}br {mso-data-placement:same-cell;}--> AIIMS 2018

• A. Both assertion and reason are false.
• B. Both assertion and reason are true and reason is the correct explanation of assertion.
• C. Assertion is true but reason is false.
• D. Both assertion and reason are true but reason is not the correct explanation of assertion.

Answer 1

The correct option is B Both assertion and reason are true and reason is the correct explanation of assertion.

The ease of liquefaction of a gas depends on their inter-molecular force of attraction which in turn is measured in terms of van der Waals constant ‘a’. Hence, the higher the value of ‘a’, greater the inter-molecular force of attraction, easier the liquefaction.
Hence, both assertion and reason are true and the reason is the correct explanation of assertion.