Monday, 29 April 2013

Normality Guide - Calculate Normality

Normality Information

Normality Definition and Calculation

Normality can be defined as - One gram equivalent of solute per liter of solution. Normality is the measure of the concentration.

Normality= gram equivalent of solute/liter of solution
number of reacting units (n)  multiply by Moles/Liter

                                         ------------------Formaula 1

Normality of solution can also be expressed in terms of mass and equivalent mass:

Normality = Mass of the solute (E) / Equivalent mass of the solute X volume of the solution in litre (V)

                                            --- --------------Formula 2

From the about information You might have got the formula , and got the answer of how to calculate Normality of any solution. Let us find out how to calculate normality with example:

Normality Example calculate 1

Suppose Nacl is present (Sodium Chloride) Now here  find the  valence (number of protons reacts) of Nacl first from the chemical reference books.

Now find the equivalent weight of Nacl : The equivalent weight is equal to the molecular weight divided by the valence.

Now sodium chloride has a valence 1 and molecular weight=58.443 so the equivalent weight will be 58.443/1= 58.443

Now 1 gm Nacl dissolved in 0.05 L of water , so by the above formula 2

Normality will be = 1 gram/ 58.443 equivalent mass X  0.05 L of solution

Answer will be 0.342 N solution.

Note: Molecular weight (MW) is sometimes also called as formula weight (FW)

Normality Example  Calculate 2

Find the normality of Ammonia, Ammonia reacts with one proton only and its molecular weight is 17.03 hence its equivalent weight will be 17.03/1= 17.03g/eq

Now one more example:

Suppose a solution contains 5.300g/L of  Sodium Carbonate, Find the normality of solution

Step 1: Find how much protons reacts with sodium carbonate, So here two protons hence Answer is 2 protons

Step 2: Find the moles = 105.99g/mol ( Ues Molecular weight )

Step 3:  Here formula 1 will be applicable

number of protons here =2
Moles = 105.99g/mol
5.300g/L solution

Hence Normality  = 2 X 5.300g/105.99g/mol
Hence normality of the given solution =0.1000 N

What is Normality, Definition of Normality, How to calculate Normality are some of the points which are discussed in this article