Question

The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol. How much energy is produced by burning 0.8210 g of naphthalene?

Answer 1

The energy produced by burning : -32.92 kJ

Further explanation

Delta H reaction (ΔH) is the amount of heat change between the system and its environment

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)

The enthalpy and heat(energy) can be formulated :

`\tt \Delta H=(Q)/(n)\rightarrow n=mol`

The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol.

The energy released for 0.8210 g of naphthalene :

`\tt Q=\Delta H* n\\\\Q=-5139.6~kJ/mol* (0.8210~g)/(128.17~g/mol)~\\\\Q=-32.92~kJ`