C4H10 = 58
C2H4和C3H6的平均相对分子质量为 58-21.6=36.4
28n+42(1-n)=36.4
n=0.4
1-n=1-0.4=0.6
C2H4和C3H6的体积比是 0.4∶0.6=2∶3