Relation between Normality and Molarity

There is a very close relation between Normality and Molarity. Normality can be described as a multiple of molarity. While molarity refers to the concentration of a compound or ion in a solution.

relationship between normality and molarity

Normality refers to the molar concentration only of the acid component or of the base component of the solution.

Normality

normality

The gram equivalent of the substance dissolved in a volume of solution in a litre is Normality. The reactive capacity of a molecule is measured in grams equivalent weight.

It is expressed as ‘N’, eq/L, or meq/L, with ‘eq’ denoting equivalents and ‘meq’ denoting millie equivalents. For titration calculations, Normality is the preferable method of measuring concentration.

Normality= gram equivalent of solute/ volume of solution in litre

It determines the chemical concentration based on the chemical reaction that is being studied. Not all reactions use this unit of measurement.

Normality is computed using grammatically equivalent weight, which is why it is rarely used. The number of ions that react in reaction determines this. This could differ depending on the reaction that occurs.

As a result, the gram equivalent weight does not remain constant. This could result in some ambiguity.

Molarity

molarity

The most frequently used measure of concentration in a solution is called molarity. Molar concentration is another term for molarity. In other words, the number of moles of a solute dissolved per litre of solution.

Molarity is denoted by mol/L. It is represented as ‘M’.

Molarity = number of moles of solute/ Volume of solute in litres

The number of moles of a substance is calculated in the following manner;

Number of moles = mass of substance/ molecular mass of the substance

Molarity changes with temperature and volume. With the increase in temperature, molarity decreases. On a similar note, when the volume of the solution increases, molarity decreases. When the number of solutes increases in the solution, so will be the morality.

The molarity of the solution also depends on the solubility of a solute. And when any additional substances are added to the solution, the molarity directly relates to the amount of solute in a solution. 

Relation Between Normality And Molarity

Molarity and Normality are related as follows:

Normality = Molarity X Molar mass /Equivalent mass

For acids, the Normality can be calculated with the following formula:

Normality = Molarity x Basicity

To know the value for basicity, count the number of H+ ions an acid molecule can give.

For bases, the Normality can be calculated with the following formula:

Normality = Molarity x Acidity

To know the value for acidity, count the number of OH ions a base molecule can give.

How to convert Molarity into Normality

how to convert molarity into normality

The below equation will help you convert M to N.

N = M x n

Where, n= the number of equivalents

For some chemicals, when n = 1, N and M are the same.

So this is the relation between normality and molarity.

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