Empirical Formula 2
Empirical Formula: The simplest ratio of the atoms present in a molecule.
Problem:
Find the empirical formula of a compound that is 48.38% carbon, 8.12% hydrogen,
and 53.5% oxygen by mass.
Strategy:
As with most stoichiometry problems, it is necessary to work in moles. The
ratio of the moles of each element will provide the ratio of the atoms of
each element.
- Get the mass of each element by assuming a certain overall mass for the
sample (100 g is a good mass to assume when working with percentages).
- Convert the mass of each element to moles of each element using the atomic
masses.
- Find the ratio or the moles of each element by dividing the number of moles
of each by the smallest number of moles.
- Use the mole ratio to write the empirical formula.