The molar masses and empirical formulas of several

Step 1 of 2

Here, the molar masses and empirical formulas of compounds are listed here. We have to find the molecular formula of each compound :

First, let’s see what is an empirical formula and molecular formula and then we see the steps to determine the molecular formula from the given data.

Empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound. The smallest whole number ratios of the subscripts of molecular formulas are derived by dividing the subscripts by the largest common factor.

For example:

The empirical formula of disulfur dioxide is \(\mathrm{S}_{2} \mathrm{O}_{2}\).

The empirical formula of ethane \(\left(\mathrm{C}_{2} \mathrm{H}_{6}\right)\) will be \(\mathrm{CH}_{3}\).

Molecular formula is a chemical formula that gives the total number of atoms of each element in each molecule of a substance.  These definite numbers of atoms present in a molecule are represented as subscripts in the molecular formula.

For Example : \(\mathrm{C}_{2} \mathrm{H}_{6}\) is the molecular formula of ethane. 1 molecule of ethane contains 2 atoms of Carbon and 6 hydrogen (H) atoms.

Steps to determine molecular formula from the empirical formula and molar mass of molecular formula :

1. We are given the molar mass of the molecular formula. So we First, we determine the molar mass for the given empirical formula.

2. We divide the molar mass of the molecular formula by the molar mass of the empirical formula and the result we get, we multiply that with the superscripts of the empirical formula and arrive at the molecular formula.