Elemental analysis of a compound, once used as a pesticide, was found to be 74.2% carbon, 8.64% hydrogen, and 17.2% nitrogen. What is the empirical formula of this compound?

Answer 1

Take a 100 g sample and that contains
74.2 g C
8.64 g H
17.2 g N
Convert to mols
74.2/12 = ?
8.64/1 = ?
17.2/14 = ?

Now find the ratio of these three elements to each other with the lowest number being 1.00. The easy way to do that is to divide the smallest number by itself (making it 1.00 of course), then divide the other values by the same number. Round to whole numbers. Those whole numbers will give you the subscripts for CxHyNz. Post your work if you get stuck.