Given below are two statement: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : SO$$_2$$(g) is adsorbed to a large extent than H$$_2$$(g) on activated charcoal.
Reason R : SO$$_2$$(g) has a higher critical temperature than H$$_2$$(g)
In the light of the above statements, choose the most appropriate answer from the options given below.

We recall the basic principle of physical adsorption: gases that are more easily liquefied are held more strongly on the surface of adsorbents such as activated charcoal. This ease of liquefaction is measured through the critical temperature, denoted $$T_c$$; the larger the value of $$T_c$$, the stronger the van der Waals forces between the gas molecules, and the greater the extent of adsorption.

Mathematically, for two gases 1 and 2 at the same temperature and pressure, we can write the qualitative relation

$$\text{Extent of adsorption}\;\propto\;T_c$$

Now we examine the two gases mentioned:

For sulphur dioxide, the experimental value is

$$T_c(\text{SO}_2)=430\;{\rm K}\;(\text{approximately}).$$

For hydrogen, the corresponding value is

$$T_c(\text{H}_2)=33\;{\rm K}\;(\text{approximately}).$$

Clearly, $$T_c(\text{SO}_2)\;>\;T_c(\text{H}_2).$$

Substituting these values in the qualitative proportionality, we conclude that

$$\text{Extent of adsorption of SO}_2\;>\;\text{Extent of adsorption of H}_2.$$

This directly supports Assertion A: “SO$$_2$$(g) is adsorbed to a large extent than H$$_2$$(g) on activated charcoal.”

The higher critical temperature of SO$$_2$$, quoted in Reason R, provides exactly the scientific explanation for the greater adsorption observed. Hence Reason R is both correct and the proper explanation of Assertion A.

Therefore, the statements match option B: “Both A and R are correct and R is the correct explanation of A.”

Hence, the correct answer is Option B.