Question

Which statement is true about an empirical formula?

Answer 1

An empirical formula is the simplest ratio of atoms in a formula unit.

The true ratio of atoms in a formula unit is called the molecular formula, also with the true molecular mass of a chemical formula.

Empirical formulas represent the lowest ratio of coefficients in a chemical formula.

Answer 2

Answer : The correct option is, It is the simplest ratio of atoms in a formula unit.

Explanation :

Empirical formula : It is the simplest form of the chemical formula which depicts the whole number of atoms of each element present in the compound.

Empirical formulas represent the lowest ratio of coefficients in a chemical formula.

Molecular formula : it is the chemical formula which depicts the actual number of atoms of each element present in the compound.  

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{molecular mass}}{\text{empirical mass}}$

For example :

As we are given the molecular formula is, $C_{10}H_{22}O_2$

In this the least whole number is, 2

So, the empirical formula will be, $C_{\frac{10}{2}}H_{\frac{22}{2}}O_{\frac{2}{2}}=C_5H_{11}_O$

Hence, the correct option is, It is the simplest ratio of atoms in a formula unit.