For real gases the relation between p, V and T is given by van der Waals equation :(p+(an^(2))/(V^(2)))(V-nb)=nRTWhere .a. and .b. are vasn der Waals constants, .nb. is approximately equal to the total volume of the molecules of a gas. .a. is the measure of magnitude of intermolecular attraction.(i) Arrange the following gases in the increasing order of .b.. Give reason.O_(2), CO_(2), H_(2), He(ii) Arrange the following gases in the decreasing order of magnitude of .a.. Give reason.CH_(4), O_(2), H_(2)

For real gases the relation between p, V and T is given by van der Waa

1.	For real gases the relation between p, V and T is given by van der Waals equation :(p+(an^(2))/(V^(2)))(V-nb)=nRTWhere .a. and .b. are vasn der Waals constants, .nb. is approximately equal to the total volume of the molecules of a gas. .a. is the measure of magnitude of intermolecular attraction.(i) Arrange the following gases in the increasing order of .b.. Give reason.O_(2), CO_(2), H_(2), He(ii) Arrange the following gases in the decreasing order of magnitude of .a.. Give reason.CH_(4), O_(2), H_(2)
Answer» Solution :(i) Molar volume occupied by the gas molecules size of the molecules and VAN der Waals. CONSTANT .b. shows the molar volume of the gas molecules. Hence, value of .b. increases as `H_(2)lt He lt O_(2)lt CO_(2)` (ii) van der Waals. constasnt .a. is the measure of magnitude of intermolecular attraction. As the magnitude of intermolecular attractions increases there is a increae in size of electron cloud in molecule. Thus, for the gases magnitude of .a. decreases as `CH_(4)GT O_(2)gt H_(2)` Greater the size of electron cloud, greater is he DISPERSION forces or London forces and higher is the polarisability of molecule.