Question
The heat of combustion of ethane and benzene is $$ - 1560$$ and $$ - 3268\,kJ\,mo{l^{ - 1}}$$ respectively. Which of two has higher efficiencyasfuel per gram and what is the amount of heat produced per gram ?
A.
$${\text{Benzene,}}41.9\,kJ\,{g^{ - 1}}$$
B.
$${\text{Ethane,}}52\,kJ\,{g^{ - 1}}$$
C.
$${\text{Benzene}},78\,kJ\,{g^{ - 1}}$$
D.
$${\text{Ethane,}}30\,kJ\,{g^{ - 1}}$$
Answer :
$${\text{Ethane,}}52\,kJ\,{g^{ - 1}}$$
Solution :
Heat produced by ethane $$ = \frac{{1560}}{{30}} = 52\,kJ\,{g^{ - 1}}$$
Heat produced by benzene $$ = \frac{{3268}}{{78}} = 41.9\,kJ\,{g^{ - 1}}$$