When 1 gram of nitroglycern, C3H5(NO3)3, decomposes to form nitrogen gas, oxygen gas, gaseous carbon dioxide, and liquid water, 1.9 kcal of heat is evolved. How much heat is evolved per mole of gas formed in the decomposition of nitroglycerine?
The answer is -90.7 kcal, but I don't know how to come about getting it.