Aim

To perform and observe the reaction between sodium sulphate and barium chloride solutions and also identify the type of reaction involved.

Apparatus and Chemical

• Beakers (250 mL)
• Test tubes
• Test tube stand
• Glass rod
• Barium chloride solution
• Sodium sulphate solution
• Distilled water

Principle

Both barium chloride and sodium sulphate dissolve freely in water to give colourless solution (use only distilled water). On mixing the two solution as curdy white precipitate of barium sulphate is obtained. This is because barium sulphate in insoluble in water and is white in colour.
BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl

It is an example of double displacement reaction. This is because in this reaction one component each of both the reacting molecules get exchanged to form the products.

Procedure

• In a clean beaker take nearly 290 mL of sodium sulphate solution and lebel it. Note its colour and appearance.
• In a clean and dry test tube take nearly 10-15 mL of barium chloride solution and lebel it. Note its colour and appearance. Put it in the stand.

• Add barium chloride solution sulphate solution with constant stirring and observe the changes produced.
• Record your observations in the notebook.

Observations and Inference

S.No.	Experiment	Observation	Inference
1.	Note the colour and appearance of barium chloride solution.	It is transparent and colourless.	Barium chloride is colourless and freely soluble in water.
2.	Note the colour and appearance of sodium sulphate solution.	It is transparent and colourless.	Sodium sulphate is colourless and freely soluble in water.
3.	Note the colour and appearance of the reaction mixture after mixing of the two solution.	(a) The precipitates formed are white in colour. (b) The precipitates formed are white in colour.	A solution of sodium chloride in water is colourless. It is freely soluble in water. Barium sulphate is white in colour. It is insoluble in water.

Both Barium chloride and sodium sulphate solutions are clear and colourless. On adding barium chloride solution to sodium sulphate solution, a curdy white precipitates is formed. It is due to the formation of insoluble barium sulphate. It is an example of double displacement reaction.

Precautions

• Use only clean and dry test tube for the barium chloride solution.
• Use only distilled water to wash the test tubes.