Question

Assertion: Noble gases can be liquefied.
Reason: Attractive forces can exist between nonpolar molecules.
A. Both assertion and reason are correct and reason is the correct explanation for assertion.
B. Assertion and reason are correct but reason is not the correct explanation for assertion.
C. Assertion is correct but reason is incorrect.
D. Assertion is incorrect but reason is correct.

Answer 1

For a gas to liquefy, the most important thing is the existence of forces of attraction. A gas can be liquefied if somehow there exists attractive forces in between the constituent molecules and any gas can be liquefied by attaining its critical temperature.

Complete answer:
Now let us understand the assertion and reason one by one.
According to the assertion, noble gases can be liquefied. This statement is true. A noble gas can be liquefied at its critical temperature. At the critical temperature, the composition of liquid and gas becomes the same. The noble gases are non-polar in nature and much more stable. This means that because of the absence of polarity, attractive forces can’t persist among the molecules of the noble gas. But, no gas is ideal in nature. So is with these noble gases. Thus, they can be liquefied if the temperature is dropped to the critical temperature of the gas.
According to the reason, attractive forces can exist between nonpolar molecules. This statement is true. The prime example where non-polar molecules have attractive forces among them is noble gases. Thus, because of the existence of these attractive forces, a gas can be liquefied. Hence, the reason is the correct explanation of the assertion.

Hence, the correct option is A. Both assertion and reason are correct and reason is the correct explanation for assertion.

Note:
The noble gases have a completely filled stable electronic configuration and due to this, their reactivity is too low. Thus, the noble gas compounds can be easily broken by the application of even a smaller stress.