Question

How can I find the molecular formula from the molar mass?

Answer 1

Hint:In order to find the molecular formula of a compound we must first know what a molecular formula is. Molecular formula is said to be a chemical notation which is used to describe the number of elements and type of elements present in a single molecule of a compound.

Complete answer:
Let us first understand about the molecular formula. Molecular formula is said to be a chemical notation which is used to describe the number of elements and type of elements present in a single molecule of a compound. The constituent element present in the chemical compound will be represented using the chemical symbol. The total number of each element present in the chemical compound is represented as the subscript following the chemical symbol. From the molecular formula, we can get the proportions of the atoms present in the chemical compound. Molecular formula will include the brackets, dashes, plus (+) and minus (-).
In order to find the molecular formula from the molar mass, we must first find the molar mass of the chemical compound.
First calculate the empirical formula molar mass. Now we have to divide the molar mass with the empirical formula molar mass. Now we will get a number close to a whole number. Then multiply that whole number with the subscripts of the empirical formula, the obtained formula is the molecular formula.

Note:
Molecular formula and the empirical formula are not the same. Empirical formula is said to be the simplest formula of the chemical compound. Molecular formula is the ‘n’ times of the empirical formula, where n is some integer multiple.
\[\text{Molecular formula}\] = \[n{\times Empirical formula}\]