Question

What is the difference between molar mass and molecular mass? (Class 9 cbse) explain properly in detail. plz

Answer 1

Both are numerically same! Yeah, You have read it correct. ;-)

But yes there are two differences you should be aware of.

Difference 1. The Units

We generally use amu ( atomic mass unit) or u (unified mass) while talking about mass of atoms, molecules and ions.

On the other hand, We generally use gram (g) per mole when we talk about molar mass.

NOTE : 1 amu=1u = 1.67 * 10^24 g

Difference 2. The Meaning

Mass of an atom is called Atomic mass. And this is the mass of 1 atom of that element (like Hydrogen).

For example the mass of 1 atom of H is 1 amu.

Similarly, Molecular mass is the mass of one molecule of that kind.

For example Molecular mass of Ca(OH)2 is 74 amu.

Molar mass is the mass of 1 mole of molecules of that element.

For example, Molar mass of hydrogen is 1 g, This means that 1 mole of hydrogen atoms will have mass around 1 g.

Note: In many formulae,, you may find the following terms interchanged:Atomic mass , Molecular mass, Formula mass and Molar mass.For quick response, just remember that molar mass is atomic mass or molecular mass in grams.I hope my answer helped you!

Answer 2

Molecular mass- it is the sum of the atomic masses of all the atoms in a molecule of the substance. It is expressed in atomic mass unit(u).
Molar mass= mass of 1 mole -is always expressed in grams, and is also known as gram atomic mass..

I hope answer is useful to you.