Question

vanderwalls equations for CH4 at low pressure ​

Answer 1

answer :

PV=RT−Pb

PV=RT−aV

PV=RT+aV

PV=RT+Pb

Solution :

The van der Waals gas equation for 1mol of gas is

(P+aV2)(V−b)=RT

At low P, volume is high. So

(V−b)=V

∴(P+aV2)V=RT

or PV=RT−aV

Hence, the correct choice is (b)

Answer 2

Answer is in the attached image

Although not sure