Acid – base titration can be used to make soluble salts by neutralizing a given amount of alkali by an equivalent amount of Acid. A conical flask contains a measured volume of sodium hydroxide solution.  And an acid HCl in this case is then drop wise added through a burette and with a universal indicator in the flask that is swirled simultaneously, the amount of Acid used is measured as the indicator changes colour. The step is repeated with the measured volume for a pure solution. 

For insoluble base such as copper(II) oxide is to be reacted with an acid, excess base is used to ensure that all Acid is used and then excess base that is unreacted is filtered. 

Limited to binary salts, used for sulfites and halides.