Experiment 14: Double displacement reaction


  • Study an example of double displacement reaction

Materials required:

  • Two test tubes
  • Sodium sulphate
  • Barium chloride
  • Dil. Sulphuric acid
  • Dropper


  • 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



  • 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


  • When a solution of sodium sulphate is mixed with a solution of barium chloride, the following double displacement reaction takes place:


    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.