If the heat of combustion for a specific compound is -1110.0 kJ/mol and its molar mass is 89.45 g/mol, how many grams of this compound must you burn to release 834.20 kJ of heat?

1 Answer
Jul 7, 2017

#67.22g# of the substance must be burned to release that much heat.


#834.20kJ((mol)/(1110.0kJ))((89.45g)/(mol)) = 67.22g#

The reason the sign was changed is because "releasing" heat in the question implies an exothermic system. That's exactly what this substance is, so the signs were matched.