Types of Double Displacement, Theory, Precautions to be Taken During the Experiment (For CBSE, ICSE, IAS, NET, NRA 2022)

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Double Displacement
Double Displacement

Materials Required

  • Test tube stand
  • Measuring cylinder
  • Two test tubes
  • Glass rod
  • Conical flask
  • Barium chloride solution
  • Sodium sulphate solution


  • Reactions occurring in the solution by exchanging ionic compounds to form new compounds are called double displacement reactions. The ionic compounds considered as reactants are water soluble. One of the products is formed as a precipitate or as a gas which is water soluble.
  • When two solutions viz sodium sulphate and barium chloride are mixed, double displacement reaction as below occurs.

Sulphate ions from the solution of sodium sulphate are displaced by chloride ions and the chloride ions from the solution of barium chloride are displaced by sulphate ions.


  • Take two test tubes, wash them with distilled water and dry them.
  • Label the test tube as P and Q.
  • Pour 5 mL of barium chloride in the test tube P and observe the colour.
  • Pour 5 mL of sodium sulphate in the test tube Q and observe the colour.
  • Take a conical flask and pour the solutions from both the test tube into it.
  • Stir the mixture added to the conical flask with a glass rod.
  • Keep it undisturbed for some time.
  • Observe the change in colour of the solution.
  • Record your results in the below-given table.


Colour of test tube P and test tube QColourless
Mixture of solution in conical flaskPrecipitation is formed

Result and Conclusion

From the above experiment 3 (D) we can conclude that the reaction occurred on mixing the solutions of barium chloride and sodium sulphate produce a white precipitate compound by exchanging their ions. This reaction is known as a double displacement reaction.

Precautions to be Taken During the Experiment

  • The test tube, glass rod, and conical flask should be washed with distilled water and dried before the experiment.
  • The volume of sodium sulphate and barium chloride should be equal.
  • Do not try to taste or touch the chemicals.
  • While combining the solutions in the mixture pour sodium sulphate first and then slowly add barium chloride to it.


Barium Sulphate is Soluble in Water. True or False?

Ans: False

Sodium Sulphate and Barium Chloride Are Ionic Compounds. True or False?

Ans: True.

The Reaction between Sodium Sulphate and Barium Chloride is Called a Double Displacement Reaction. Why?

Ans: Because they exchange their ions.

Can You Define Double Displacement Reaction?

Ans: The reactions where two compounds exchange their salts to form an insoluble compound.

What Happens when You Mix Sodium Sulphate with Barium Chloride?

Ans: A white precipitate is formed.

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