选C
设烷烃和烯烃分子式为:CnH2n+2、CnH2n ,混合气体中烷烃体积为x
CnH2n+2 + 3n+1)/2 O2--->nCO2+(n+1)H2O CnH2n + 3n/2 O2--->nCO2 + nH2O
X nx (n+1)x 1-x n(1-x) n(1-x)
可得:nx+ n(1-x)=2 ,(n+1)x+n(1-x)=2.4
解得:x=0.4,则混合烃中烷烃和烯烃的体积比是:0.4:0.6=2:3
选C
设烷烃和烯烃分子式为:CnH2n+2、CnH2n ,混合气体中烷烃体积为x
CnH2n+2 + 3n+1)/2 O2--->nCO2+(n+1)H2O CnH2n + 3n/2 O2--->nCO2 + nH2O
X nx (n+1)x 1-x n(1-x) n(1-x)
可得:nx+ n(1-x)=2 ,(n+1)x+n(1-x)=2.4
解得:x=0.4,则混合烃中烷烃和烯烃的体积比是:0.4:0.6=2:3