If the heat of combustion for a specific compound is 11200 k

If the heat of combustion for a specific compound is -1120.0 kJ/mol and its molar mass is 92.59 g/mol, how many grams of this compound must you burn to release 556.30 kJ of heat?

Solution

Molar heat of combustion = -1170.0 kJ/mol

Heat required = 239.00 kJ of heat

Number of moles = 239/1170 = 0.20427 moles

Weight required = number of moles * molar weight = 88.57 g/mol * 0.20427 moles = 18.09213 gms