Question

How do you calculate the molar mass of hexane?

Answer 1

Hint: We must always remember that Molar mass is different from the Molecular mass. Molar mass is also called the Molecular weight. Molar mass of the chemical compound is the mass of one mole of the compound.

Complete step by step answer:
First, what is a Molar mass? Molar mass, also called as the Molecular weight, is the mass of one mole of the substance. It is expressed in the units of $$gmo{l}^{-1}$$.
- We need to follow the following steps to calculate the molar mass.
- First, we have to identify the formula of a given compound or molecule.
- Then determine the number of moles of atoms present in the given compound or molecule.
- we have to multiply the mass of each atom present in the compound with the number of moles of the atom.
- Do this for every element present in the compound.
- Finally add all these values.
- The obtained value is expressed in $$gmo{l}^{-1}$$.
Now let us come to the given question.
The molecular formula of hexane is $$C_6{H}_{14}$$. In hexane there are six carbon and fourteen hydrogen.
Molar mass of hexane = Molar mass of carbon + molar mass of hydrogen.
Molar mass of hexane = $$6\times 12.011+14\times 1.00796$$
Molar mass of hexane = $$86.178gmo{l}^{-1}$$
Therefore, the molar mass of hexane was found to be $$86gmo{l}^{-1}$$.

Note:
Comparison between molar mass and Molecular mass are given below:

MOLAR MASS	MOLECULAR MASS
Molar mass is said to be the mass of one mole of the substance.	Molecular mass is the mass of the molecule.
It is expressed in $$gmo{l}^{-1}$$.	It is expressed in amu.
It is also known as Molecular weight.	It determines the mass of a single molecule.