Molar and
normal solutions are used in the chemical analysis of raw materials. A specific
amount of chemical (solute) is dissolved to obtain the solution of required concentration
(molar or normal solutions).

## A. Molar Solutions

Molar
solutions are prepared by dissolving the gram molecular weight of the solute
making 1 liter of solution. It means, to prepare 1 liter solution, we have to
dissolve the solute equal to the molecular weight of the solute in grams.

**Example 1**

Preparation
of 1M solution of H

_{2}SO_{4}
Molecular weight
of H

_{2}SO_{4}= 2+32+64 = 98
We require 98
grams of H

_{2}SO_{4}(100%) to prepare 1 liter of 1M H_{2}SO_{4}solution.**Example 2**

Preparation
of 1M solution of NaOH

Molecular
weight of NaOH =23+16+1 = 40

We require 40
gm of NaOH (100%) to prepare 1 liter of 1M NaOH solution.

## B. Normal Solutions

Normal
solutions are prepared by dissolving gram equivalent weight of solute making 1
litre of solution. It means, to prepare 1 liter solution, we have to dissolve the
solute equal to the equivalent weight of the solute in grams.

Equivalent
weight of any chemical is calculated by dividing the molecular weight with its valence.
Valency is the number of ions that can be displaced.

Equivalent weight
= Molecular weight / Valency

**Example**

Preparation
of 1N solution of H

_{2}SO_{4}
Molecular weight
of H

_{2}SO_{4}= 2+32+64 = 98
Valency of H

_{2}SO_{4}= 2 (2 hydrogen ions)
Equivalent
weight = 98/2 = 49

We require
49 gm of H

_{2}SO_{4}(100%) to prepare 1 litre of 1N H_{2}SO_{4}solution.**Note:**If the solute is not 100% pure then calculate the required quantity using the following formula.

Actual
quantity (gm) =

__Theoretical quantity (gm) x 100__
Purity
(%)

For example
you require 98 gm of H

_{2}SO_{4}to prepare 1 liter of 1M H_{2}SO_{4}but the actual purity of H_{2}SO_{4}is 98% therefore calculate the actual quantity as below.
Actual
quantity (gm) = (98 x 100)/98 = 100 gm