Question

An analysis of 5.0 grams of a sample of a compound is found to contain 1.6 percent hydrogen (H), 22.2 percent nitrogen (N), and 76.2 percent oxygen (O). Determine the empirical formula of the compound.

Answer 1

We are given with the mass percentage of the elements. Taking a 100-gram basis, we convert the mass of the reactants to moles. Hydrogen is equal to 1.6 moles , nitrogen is equal to 1.3058 and oxygen is equal to 4.7625 moles. We divide each number to the least amount. Hence H is 1.22, N is 1.00 and O is 3.65. Answer is HNO3, nitric acid.