# Molar Concentration

What is molar concentration? How to calculate it? Read on, to find all the answers. . .

Omkar Phatak

*Kilo*' is a unit for specifying mass of any substance. A mole of any chemical substance is the molecular weight of that substance, directly expressed in the unit of grams.

^{23}molecules. So taking a mole of a substance is exactly quantifying the number of molecules that you are using in your chemical reaction.

Definition

The molar concentration or molarity of a specific chemical in a solution can be defined to be the number of moles dissolved in unit volume of the solution. In other words, it defines how many moles of any solute, will exist in unit volume of its solution. The commonly used unit for it is 'Mol/Liter' or Mol/L.

Formula

Here is the molarity formula, which you must remember or be able to deduce, to calculate molar concentration accurately.

The above formula can also be used for calculating molar concentration of ions and molecules.

Calculation

To execute the calculation, you need to know two parameters. One is the number of moles of solute and the second is the volume of the solution. To be able to calculate the moles of a substance or solute, first calculate its molecular weight, by extracting the atomic weight values of its constituent atoms.

Solved Example

Suppose that about 117 gm NaCl (common salt) is dissolved in two liter (V) of distilled water. What will be the molar concentration of salt in the water solution?

*Molar Concentration = n / V = (2 moles of NaCl) / (2 Liters of Water) = 1 Mol/L*