Normality

Normality is also known as equivalent concentration. It is a measure of equivalent concentration of a solution. The normality is understood as the gram equivalent weight per liter of solution. The role of solute in this reaction determines the normality of a solution.

Normality Equation

The equation of normality is expressed as:

\(Normality \; \left ( N \right ) = \frac{Equivalents \;of\; Solute}{Liters \; of \; Solution}\)

The equation for normality of the solution in terms of mass and equivalent mass can be expressed as:

\(Normality \; \left ( N \right ) = \frac{Mass \; of \; the \; solute}{Equivalent \; mass \; of \; the \; solute(E)\;\times Volume \; of \; the \; solution \; in \; litres(V)}\)

The normality of a substance in terms of weight is expressed as:

\(Normality \left ( N \right ) = \frac{Wg}{Eg /equiv \times V litre}\)

\(Normality \left ( N \right ) = \frac{Wg}{Eg /equiv \times V litre} = \frac{W equiv/L}{W \times V}\)

Normality Unit Symbol

The unit symbol for normality is N. It also denote \(equiv/L\) (equivalent per liter) which is also known as normality.

Usage of Normality

There are many uses of normality, but three common areas where it is used as a measure of solution reactive.

  1. Normality is used to express hydroxide ion’s \(\left (OH^{-} \right )\) or hydronium ion’s \(\left (H_{3}O^{+} \right )\) concentration of solution in acid-base chemistry.

  1. Used in precipitation reactions to measure the number of ions.

  1. In redox reaction, it describes the number of electrons that an reducing agent or oxidizing agent can donate or accept.

Normality Examples

Question: Calculate the morality of \(\small 0.650 N HCl\)

Solution:

Given:

Normality of HCl = \(\small 0.650 N\)

It means it has \(\small 0.650\) equivalents of HCl in \(\small 1000 ml\) of solution.

The HCl produces only 1 proton in its solution.

\(\small \; Therefore, \; 0.650\) equivalents = \(\small 0.650\) moles in \(\small 1000 ml\)

So, the molarity = \(\small 0.650 M\)

You can also use the normality calculator for more complex calculations.


Practise This Question

Which one of the following is reduced by H2O2 is basic medium