Question

Assertion: Greater the value of van der Waals constant 'a', easier is the liquefaction of gas.
Reason: 'a' indirectly measures the magnitude of attractive forces between the molecules.

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

Answer 1

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

Answer:-

The van der Waals equation is given as: $(P+\frac{a{n}^2}{V^2})(V-nb)=nRT$

The ease of liquifaction 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.