Normality Formula

Normality Formula

The term normality is a term used in chemistry to define the molar concentration (C_i)divided by an equivalence factor f_eq. It is denoted by the letter N, and the normality formula is:

Normality N=C_i/f_eq

The unit symbol “N” is used for denoting “eq/L” (equivalent per liter) which is nothing but normality itself. Even though losing favor, medical reporting of serum concentrations in the measurement “meq/L” (= 0.001 N) still takes place.

There are three common areas where normality is used as a measure of reactive species in solution:

• In the case of acid-base chemistry, normality is used to express the concentration of hydronium ions (H3O+) or hydroxide ions (OH−) in solution. Here, the inverse of the equivalence factor will be an integer value. Each solute can produce one or more equivalents of reactive species when dissolved.
• When it comes to redox reactions, the equivalence factor describes the number of electrons a reducing or oxidizing agent can donate or accept. Here, the inverse of the equivalence factor can have a fractional (non-integer) value.
• In the case of precipitation reactions, the equivalence factor measures the number of ions that precipitate in a given reaction. Here, the equivalence factor is an integer value.

The normal concentration of an ionic solution is connected to its electrolytic conductivity through the equivalent conductivity. 

 
Normality is a term commonly used in inorganic chemistry. Want to learn more about that? Teachmint has chemistry notes – and notes of every subject that is taught in schools and colleges all over the world for that matter – together in one place! Click here to access it right away!