Difference Between Molar mass and Molecular mass

In chemistry the substance is usually measured using molecular mass and molar mass. They are very important concepts in chemistry. Expression of molar mass is grams per mole. It can also be expressed as kilogram per mole. Molecular mass is expressed in atomic mass units.

Molecular mass:

Molecular mass of a compound is defined as the mass of one molecule. Molecular mass differs because of the isotopes. The unit in which molecular mass is measured is amu. Amu stands for atomic mass units.

Molar mass:

It is defined as the mass of substance for a given amount. The amount of molecules or atoms or compounds present in one mole of substance is given by this. Molar mass SI unit is g/mol

To make you understand how molar mass and Molecular mass is different from each other, here are the some of the major differences molar mass and molecular mass:

Difference between Molar mass and Molecular mass
Refers to mass of a mole of a substance Refers to the mass of molecules
Also known as molecular weight It determines the mass of a single molecule
SI unit is g/mol to use in higher calculations Measured in amu
It is defined as the mass of Avogadro number of atoms/molecules or compounds Defined as the sum o the atomic masses of all the atoms present in a molecule of a substance.
Measurement given to compounds, atoms or molecules Determined only in molecules
Less accurate than molecular mass Accurate to use in higher calculations
Example: Mass of 1 mole of oxygen is 15.9994 grams. Therefore, the molar mass = 15.9994 g/mol Example:

Molecular mass of Ca(OH)2 = 74 atomic mass units

These were some important difference between molecular mass and molar mass. To know differences between other topics in chemistry you can register to BYJU’S or download our app for simple and interesting content. India’s largest k-12 learning app with top-notch teachers from across the nation with excellent teaching skills. Find notes, question papers for other subjects like Mathematics, Physics, Biology and various competitive exams as well. Enjoy learning with great experience. Learning is no more boring with BYJU’S.

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  1. What is the relationship between molar mass and formula mass?

    1. The formula mass of a compound is the sum of the atomic masses of the atoms in its empirical formula. On the other hand, the molar mass of a compound is the mass of one mole of that compound.

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