During the complete combustion of one mole of butane, 2658 kJ of heat is released. The thermochemical reaction for this change is:

1. 2C4H10(g)+13O2(g)8CO2(g)+10H2O(l); 
cH=-2658.0 kJ mol-1
2. C4H10(g)+132O2(g)4CO2(g)+5H2O(l); 
cH=-1329.0 kJ mol-1
3. C4H10(g)+132O2(g)4CO2(g)+5H2O(l); 
cH=-2658.0 kJ mol-1
4. C4H10(g)+132O2(g)4CO2(g)+5H2O(l); 
cH=+2658.0 kJ mol-1
 
 


HINT-Heat of combustion is heat released when 1 mole of any substance is burned in presence of oxygen 
EXPLANATION (3)
 
 Given that, the complete combustion of one mole of butane is represented by thermochemical reaction as
C4H10(g)+132O2(g)4CO2(g)+5H2O(l)
We have to take the combustion of one mole of C4H10 and cH should be negative and have a value of 2658 kJ mol-
The answer is option third.