Procedure

• The given barium chloride solution is made up to 100mL in a standard flask.

• 20mL of solution is pipetted into a 250 mL beaker.

• About 5mL 2N HCl is added and diluted to 150mL with distilled water.

• The solution is heated to boiling and a hot solution of 4N H₂SO₄ (10 - 15mL) is added drop by drop with constant stirring, till the precipitation is complete.

• The solution containing the precipitate is heated in a water bath for 5 minutes.

• The precipitate is allowed to stand for an hour.

• The clear solution is decanted through an ashless filter paper (Whatman No. 40).

• The precipitate is washed with hot distilled water to free sulphate ions.

• The particles adhering to the sides of the beaker and glass rod are removed by a policeman.

• Finally the precipitate is washed once again.

• The dried filter paper is folded and placed in a crucible which has been previously weighed.

• The filter paper with the precipitate is first incinerated on a Bunsen burner by a low flame and then transferred to an electric burner.

• The crucible is transferred to a desiccator and cooled.

• When cold, the crucible is weighed.

• Heating, cooling and weighing are repeated till concordant values are obtained.

  Calculation:

  Mass of crucible + lid = a g

  Mass of crucible + lid + Barium sulphate = b g

  Mass of Barium sulphate = (b - a) g

  233.36 g of barium sulphate contain 137.36 g of barium.

  Mass of barium in (b - a) g of barium sulphate =

  Therefore, Mass of barium in the whole of the given solution =

  Result:

  Mass of barium in the whole of the given solution = ____________ g