P(V−b)=RT
101.325(V−b)=R×273......(1)
10132.5(0.011075V−b)=R×273.....(2)
Divide equation (1) by equation (2)
101.325(V−b)10132.5(0.011075V−b)=R×273R×273
101.325(V−b)=10132.5(0.011075V−b)
(V−b)=100(0.011075V−b)
V−b=1.1075V−100b
99b=0.1075V
b=0.0010858V.....(3)
Substitute (3) in (1)
101.325(V−0.0010858V)=8.314×273
V=22.4dm3=22400cm3
r=(V×34NΠ)1/3r=(22400×34×6.023×1023×3.1416)1/3=2.07×10−7cm=2070pm