Imagine being able to use your computer to make phone calls with the help of special software and a microphoneâand bypassing your phone company and their charges.
So O2 has zero of heat of formation (or enthalpy of formation). The enthalpy of a reaction is defined like this: H = Hproducts-H reactants. The enthalpy of reaction in this case, is the same as the heat of combustion. Hproducts is obtained summing the heats of formation.
The standard enthalpy of combustion of toluene is - 3910 kJ/mol. this is the value for the substance quoted in data tables which are nothing to do with this question. The /mol refer to toluene.This is the amount of heat you could expect to be released when 1 mole of toluene is burned in oxygen.t is nothing to do with the calorimeter. The heat released by the (1.55/92.134) mole of toluene will be 65.779 kJ. In your calculation 1.55g = 142.81g is incorrect-I think you have mistaken 1.55 as a number of moles and multiplied it by the mass of 1 mol (1.55 x 92.134 = 142.81g.