Molar

A term describing a quantity of matter, e.g. a molar volume is the volume of a mole of material.
The term 'molar' is also used for solutions with a concentration (molarity) equal to 1 mol / L.

Molar fraction
Mole fraction

Molar mass
Molarity
Mole

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Mole fraction
Molar fraction

The mole fraction (molar fraction) yA of a substance A in a mixture is equal to the relationship between the quantity of matter of A (denoted by Na) and the total quantity of matter arising from all the components of mixture (denoted by N):

yA = NA / N

Molar mass

The molar mass (molecular weight) of a substance B is the mass of a mole of that substance B. It is calculated from the atomic masses of the elements which comprise the substance. The molar mass MB is related to the mass mB of a sample by the relation

MB = mB / nB

in which nB is the quantity of B.

Molarity

Word usually used to indicate the concentration c(B) of a substance B contained in volume V according to the relation:

c(B) = n(B) / V

This term describes the concentration of a substance in a solvent.

It is expressed in mol/L, i.e. a solution containing 1 mol/l is called "a molar solution" and such a solution is denoted as a "1M solution".

Mole

An international unit of matter.

It is defined as the quantity of matter which contains as many elementary entities as there are atoms in 0,012 kg of carbon 12.

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