Consider the following graph of `Z vs 1/V_m` drawn at low pressure and inversion temperature, using the virial form of vanderwaal's equation :
`Z=1+(b+1/(RT))1/V_m+b^2/V_(m^2)+b^2/V_(m^3)`+....
Find crictical molar volume `(V_c)` in `cm^3` ?

Answer

6

Explanation

`Z=1+(b-a/(RT))1/V_m` (at low P)
At inversion temperature
`T=(2a)/(Rb)`
`Z=1+(b-(a/(Rxx2a))/(Rb))1/V_m=1+(b-b/2)1/V_m=1+b/2xx1/V_m`
slope`=b/2 " " =(1.02-1.01)/(0.011-0.001)=0.01/0.01=1`
`b=2 cm^3`
`V_c=3b=6 cm^3`