Objective
- Study an example of double displacement reaction
Materials required:
- Two test tubes
- Sodium sulphate
- Barium chloride
- Dil. Sulphuric acid
- Dropper
Procedure:
- Take 0.5g of sodium sulphate in a test tube and label it as A . Add 5ml water
- In another test tube, take 0.5g of barium chloride, label it as B and add 5ml water
- Transfer the solution from test tube A to the test tube B.
- Mix the two solutions with gentle shaking.
- Observe the white precipitate of barium sulphate.
- Let the solution settle down and observe barium sulphate settling at the bottom
- Take out excess water carefully using the dropper. Add dil sulphuric acid and shake
Findings:
Conclusions:
- Double displacement reaction has taken place with formation of white precipitate of barium sulphate in the test tube. Barium sulphate is insoluble in dil sulphuric acid
Theory:
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When a solution of sodium sulphate is mixed with a solution of barium chloride, the following double displacement reaction takes place:
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Na2SO4 (aq) + BaCl2 (aq) --> BaSO4 (s) + 2NaCl (aq) - In this reaction, sulphate ions (SO42- ) from sodium sulphate are displaced by chloride ions (Cl-) and chloride ions in barium chloride are displaced by sulphate ions. As a result, a white precipitate of barium sulphate is formed and sodium chloride remains in the solution.