# What is the empirical formula of H2O2?

Nov 27, 2015

The empirical formula is the simplest whole number ratio that defines constituent atoms in a species.

#### Explanation:

Given the above definition the empirical formula of hydrogen peroxide is simply $O H$. Note that the molecular formula is ALWAYS a multiple of the empirical formula. That is ${\left(E F\right)}_{n} = M F$; where $E F , M F$ are empirical and molecular formulae respectively and $n$ is a whole number (what does $n$ equal here?).

What are the empirical formulae of benzene, ethylene, and acetylene; the molecular formulae are ${C}_{6} {H}_{6}$, ${H}_{2} C = C {H}_{2}$, and $H C \equiv H C$, respectively.

Nov 28, 2015

The empirical formula for the molecular formula $\text{H"_2"O"_2}$ is $\text{HO}$.

#### Explanation:

The empirical formula of a compound is the lowest whole number ratio of elements in the compound. This ratio becomes the subscripts for the empirical formula.

The molecular formula $\text{H"_2"O"_2}$ is a multiple of the empirical formula. We can know this because the ratio of $\text{2H":2"O}$ is not the lowest whole number ratio. By dividing the subscripts by $2$, we can determine the lowest whole number ratio, which is $\text{1H":1"O}$. Therefore, the empirical formula for $\text{H"_2"O"_2}$ is $\text{HO}$.

Sometimes the molecular and empirical formulas are the same.