Question

若1 mol某气态烃CxHy完全燃烧，需用3 mol O₂，则(    )

A.x=2,y=2                      B.x=2,y=4

C.x=3,y=6                      D.x=3,y=8

Answer 1

B

解析:

根据烃燃烧的通式：C_xH_y+(x+y/4)O₂xCO₂+y/2H₂O,得出x+y/4=3。将选项逐一代入：A项x=2,y=2,x+y/4=2.5；B项x=2,y=4,x+y/4=3；C项x=3,y=6,x+y/4=4.5,D项x=3,y=8,x+y/4=5。所以B正确。