For real gases, van der Waal's equation is written as `[p + (an^(2))/(V^(2))] (V - b) = nRT` where a and b are van der Waal's constant. Two sets of gases are
(I) `O_(2), CO_(2), H_(2) " and " He` (II) `CH_(4), O_(2), H_(2)`.
The gases given in set I in increasing order of b and gases given in set II in decreasing order of a are arranged below. Select the correct order from the following :

Options

A. (I)` He lt H_(2) lt CO_92) lt O_(2)`
(II) `CH_(4) gt H_(2) gt O_(2)`
B. (I) `O_(2) lt He lt H_(2) lt CO_(2)`
(II) `H_(2) gt O_(2) gt CH_(4)`
C. (I) `H_(2) lt He lt O_(2) lt CO_(2)`
(II) `CH_(4) gt O_(2) gt H_(2)`
D. (I) `H_(2) lt O_(2) lt He lt CO_(2)`
(II) `O_(2) gt CH_(4) gt H_(2)`

Answer

C

Explanation

`a prop` intermolecular attractive forces `b prop` Effective size of the molecules `:.` order should be
(I) `H_(2), lt He lt O_(2) lr CO_(2)`,
(II) `CH_(4) gt O_(2) gt H_(2)`