What is the Empirical Formula of...

Question

A sample of amphetamine sulfate is used by some physicians for the treatment of hyperactive children. What is the empirical formula if it decomposes to 23.2 g carbon, 13.7 g oxygen, 6.9 grams sulfur, 1.61 moles hydrogen, and 6.45 moles nitrogen.

Answer 1

This is really a "grams to moles" question.

For each element, divide grams by atomic mass to get moles.  That gives you the ratio of moles which is the same thing as a ratio of atoms in the molecule.

Then divide through by the smallest.  You should get (near enough) whole numbers, or numbers which are obviously very close to fractions. If you have fractions, multiply through to get rid of them.

What you have then is the empirical formula that you are after.