Solution



Back 		Given the heat capacity of the apparatus, not the specific heat capacity of the liquid, use the formula
E = Heat capacity

Heptane
E = 8.5 5.7 = 48.45 kJ
1 g releases 48.45 kJ of heat
1 mole heptane () = 712 + 161 = 100 g
= 4845 kJ
Heat of combustion of heptane = -4845 kJ

Methylbenzene
E = 8.5 5.0 = 42.5 kJ of heat
1 g releases 42.5 kJ of heat
1 mole methylbenzene () = 712 + 81 = 92 g
= 3910 kJ
Heat of combustion of methylbenzene = -3910 kJ