what is the difference between molarity and normality?

Molarity is number of gram molecular weights per liter of solution. Normality is number of equivalent weights per liter of solution. An equivalent weight is the molecular weight divided by the valence.

For example: Suppose that a solution of H2SO4 is 1M. Then it is 2N. Normality is twice the molarity in this case.

Molarity is the number of moles per liter of solution. Normality is the number of equivalents of a specific ion or element in a compound (I will explain later). The units for each are M (molarity) and N (normality).

Example: Lets say you have a 1M solution of HCl and a 1M solution of H2SO4. Because there is 1 Hydrogen ion per Mole of solution, the normality would be 1 N. If the solution was 1 M of H2SO4, then there are 2 Hydrogen ions per mol of solution and the normality would be 2 N in terms of Hydrogen ions.

**Normality is usually only used when talking about acids and bases such as H+ ions and OH- ions.