Question

An oxide of iron consists of 70% mass of iron and the rest oxygen. Find its simplest formula?

Answer 1

Explanation:

tells you which types of atoms (elements) are present in a molecule and their levels. Percent composition can also tell you about the different elements present in an ionic compound as well.

Let's look at two examples

The molar mass of

H

2

O

is 18 g/mol

The hydrogens make up 2g (since each mole of hydrogen is 1g)

The oxygen makes up 16g.

The percent composition of the compound is:

H = (2g/18g) x 100 = 11.1%

O = (16g/18g) x 100 = 88.9%

Percent composition can be calculated the chemical formula of a compound, or it can be determined experimentally.