Nitroglycerin molar mass

Calculate the percent composition of nitroglycerine, C3H5N3O9, using molar masses instead of formula masses. 

Determine the molar mass of each of the following compounds, all of which have been used as explosives (a) lead azide, PbN, (b) nitroglycerin, C3H5N5O9, (c) mercury fulminate, Hg(ONC)2... 

Looking at these three compounds, we see that nitroglycerin has the smallest molar mass even though it clearly contains the most atoms per molecule. Does this make sense The key factor is that both lead azide and mercury fulminate contain elements with large molar masses, so it is not surprising that nitroglycerin is the least massive of these three molecules. 

The enthalpy of combustion of nitroglycerin is —1541 kj/mol. (a) Using this and the data from experiments conducted in the Caloiimetiy simulation (eChapter 5.5), determine the molar mass of nitroglycerin, (b) Explain how your answer to part (a) would te affected by the use of a poorly insulated calorimeter. 

---