Question

How can I calculate the empirical formula of an oxide?

Answer 1

Empirical formula represents the simplest relative whole number ratio of the atoms of each element present in a molecule of the substance. The ratios hold true on the molar level as well. If we know the molar amounts of each element in a compound, we can determine the empirical formula.
Thus ${{\text{H}}_{2}}\text{O}$ is composed of two atoms of hydrogen and 1 atom of oxygen.

Complete step by step answer:
As we know empirical formula represents the simplest relative whole number ratio.
For example: CH is the empirical formula of benzene. It indicates that benzene is composed of carbon and hydrogen in the ratio of $12\ :\ 1$ by mass.
To calculate empirical formula of an oxide follow these steps:
First write elements involving only the symbols.
Find out the atomic mass of the respective elements.
Percentage composition of the compound is determined by quantitative analysis.
Then find the moles of atom
$\text{Moles of an atom}=\dfrac{\text{Actual weight}}{\text{Atomic weight}}$
This percentage of element is divided by its atomic mass. It gives the atomic ratio of the elements present in the compound.
Atomic ratio of each element is divided by the minimum value of atomic ratio to get a simple ratio of atoms.
If the simplest ratio is fractional, then the values of the simplest ratio of each element is multiplied by the smallest integer to get the simplest whole number.
Lastly the elements are written side by side with their respective whole number as subscript at the lower right hand corner of the symbol.

Note: Molecular formula can be obtained from empirical formula if molecular mass substance is known. When the empirical formula is found.
To find the ratio between the molecular formula and the empirical formula. Basically, the mass of the empirical formula. Basically, the mass of the empirical formula can be computed by dividing the molar mass of the compound by it. Multiply every atom by this ratio to compute the molecular formula.
Elemental analysis can be used to identify percentages of each element from which empirical formula is identified.