# What is the difference between molar mass and molecular mass?

May 25, 2016

Discussed below

#### Explanation:

The molecular mass is a relative mass of a molecule of a substance ( a compound or an element )measured by the ratio of the mass of one molecule of the substance to the mass of $\frac{1}{12} t h$ part of ""_6^12C atom.
It is a unitless quantity,being the ratio of two masses.
The tiny constant mass of $\frac{1}{12} t h$ part of the mass of "_6^12C atom is also considered as unit of mass and is known as ‘amu’ or ‘u’.
$1 \text{u or amu} = 1.6 \times {10}^{- 24} g = \frac{1}{N} g$
But actual mass of one molecule of carbon dioxide molecule is $44 u$
The molar mass of a substance (a compound or an element) is the mass of 1 mole or Avogadro’s number of the molecules of that substance expressed in $\frac{g}{m o l}$ unit
The molar mass of carbon dioxide is $44 \frac{g}{m o l}$