Is there a relationship between normality and molarity?
Molarity is probably the most commonly used chemical unit of measurement, and is defined as the number of moles of a solute dissolved in a litre of solution (the mole being the SI base unit for the amount of a substance). By comparison, Normality is defined as the number of equivalents of solute per litre. Normality can only be calculated by examining chemical reactions for the solute. For example, take the neutralisation of sulphuric acid using potassium hydroxide. By studying the reaction, it is possible to determine the proton exchange number to determine the normality of the sulphuric acid. The equation for this reaction is: H2SO4 + 2KOH –> K2SO4 + 2H2O: Normality = molarity x n (where n = the number of protons exchanged in a reaction). When H2SO4 is neutralised by KOH, H2SO4 provides two protons to form 2H2O. Thus, a solution of 0.25M H2SO4 has a normality of 0.5N. Normality is particularly useful in titrations calculations using the following formula: NaVa = NbVb, where N = norm
