物质的量之比 CO2 :H2O =3:4n(烃)= 0.112L/22.4L/mol=0.005 mol碱石灰吸收 CO2和H2O3a*44+4a*18=1.02a=0.005n(CO2)=0.015moln(H)=0.04moln(烃):n(C):n(H)= 0.005:0.015:0.04= 1:3:8烃分子式为 C3H8