Normality (N)

•Frequently used for acids and bases

•A function of number of H+ per mole of acid or OH- per mole of base

•Formula:

•N = (Molarity) the number of H+ or OH-         mole

•Units: normal = N

•

•What is the normality of 1 M HCl?

–One H+ is generated per mole so 1 M HCl is also 1 N HCl

•What is the normality of 1 M H2SO4?

–Two H+ are generated per mole so 1 M H2SO4 is 2 N H2SO4

•What is the normality of 2 M NaOH?

–One OH- is generated per mole so 2 M NaOH is 2 N NaOH

•Can be used for other ions like Ca+2, PO4-3 etc based on number of ions per mole and their charge

•Weight/Volume Percent (w/v%)

   W  %  =  grams of solute  X 100 %

   V            total milliliters of solution

•Weight/Weight Percent (w/w%)

    W  %  =  grams of solute  X 100 %

  W             total grams of solution

•Volume/Volume Percent (v/v%)

  V  %  =  milliliters of solute  X 100 %

  V             total milliliters of solution

b) The USP lists the solubility of drugs as the number of ml of solvent in which 1 g of solute will dissolve. E.g. 1g of boric acid dissolves in 18 mL of water, and in 4 mL of glycerin.