Dimethylhydrazine, the fuel used in rocket propulsion systems, is made of carbon, hydrogen, and nitrogen atoms. A 2.859 g sample of this compound is burned in excess air, and produces 4.190 g of carbon dioxide and 3.428 g of water. What is the empirical formula? (molar masses: Co2= 44.01g/mol; H2O= 18.02g/mol) I was wondering do I predict the reactants? and " the compound is burned" what is the compound? Im not use to this question because im usually given the percents in the compound so i dont know how to start off this question... K well igot a ratio of 2/1 for H2O and Co2 but i was wondering should i find the percent composition of C and H then add and subtract from 100? to get the percent of N and start the work from there? and to find the percent composition should i find it from CO2(H2O) or seperately?