# Whats the difference between mol, amu, atomic mass, molecular mass, formula mass, and molar mass?

## What is the difference between atomic mass, molecular mass molar mass and formula mass

Molar mass is the mass in grams of one mole of a given substance.

,Atomic mass is the mass of one sole atom measured in terms of amu (most often),Molecular mass is the mass, measured in amu, of a molecule.

,Mol is the unity of amount of substance: in the SI brochure one reads (literally),1.

The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.

012 kilogram of carbon 12; its symbol is u201cmolu201d.

2.

When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles.

,2.

When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles.

,SI Brochure, 8th edition, http://www.

bipm.

org/utils/common/pdf/si_brochure_8_en.

pdfFormula mass - the mass of both ionic and molecular compounds in a minimum proportion.

As this is identical, in the case of molecular compounds, by logical reasons, this concept is only usefull in the ionic case, where compounds do not form molecules.

In this second sense, the concept of formula mass corresponds to the molar mass of a formula unit.

,,Next time try to google a little.

nBest regards.

## Difference between molar mass and atomic mass

The molar mass of a compound tells you the mass of 1 mole of that substance.

In other words, it tells you the number of grams per mole of a compound.

The units for molar mass are, therefore, grams/mole.

An atomic mass is unit less and defined as precisely 1/12 the mass of an atom of carbon-12 not in motion.

## SI unit of molar mass

Well text{mass} simply has units of text{grams/kilograms}u2026 On the other hand, text{molar mass} has units of gu2022mol^{-1} u2026 that is MASS per Avogadrou2019s number of particlesu2026 And typically, chemists deal with GRAM quantitiesu2026the use of kilogram masses would be RARE in the preparative organic, or inorganic laboratoriesu2026,And we see this dimensionally when we determine the molar quantity of a given mass of stuffu2026i.

e.

,text{moles of stuff}=dfrac{text{mass of stuff in grams}}{text{molar mass of stuff in grams PER mole}}And the quotient gives units of u2026.

,dfrac{g}{gu2022mol^{-1}}=dfrac{1}{mol^{-1}}=dfrac{1}{frac{1}{mol}}=mol u2026,u2026 as requiredu2026

## Molecular mass unit

There is a cyclopean difference between molecular mass and formula mass.

,Molecular mass is the mass of a given molecule or compound but now the clinch here is that it remains neutral despite the presence of zillions of molecules.

For ex: Molecular mass of CO2 = 12*1 + 16*2=44.

2.

But, now the formula mass is something different.

IT IS THE MOLECULAR MASS OF THE WHOLE COMPOUND CONTAINING X NO.

OF MOLECULES OF THAT COMPOUND.

Let me clarify it with example: Like we have to find the formula mass of 10Na2SO4.

H2O= 10[23*2+32+16*4+2*1+16*1] = 10*180= 1800.