Many cigarette lighters contain liquid butane, C4H10(l)

Answer:

The standard enthalphy of formation of C4H10(l) is -125.58 KJ / mol

C4H10(l) + (13/2)O2 (g) ----> 4CO2 (g) + 5H2O (l) : ΔH = ?

ΔH = ΔH products - ΔH reactants

     = 4* ΔH CO2 (g) + 5 * ΔH H2O (l) - ( ΔH C4H10(l) + (13/2) *ΔH O2 (g) )

     = 4 * -393.509 KJ / mol + 5*-285.83 KJ / mol ) - ( -125.58 KJ / ml + (13/2) * 0 )

     = -2877.6 KJ / mol

Molar mass of C4H10 = 4 * 12 + 10 * 1 = 58 g / mol

that is for 58 g of C4H10 the heat releseased is 2877.6 KJ

So for 2g of C4H10 the heat releseased is = (2877.6 KJ * 2 ) / 58

                                                            = 99.227 KJ