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

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Materials Required

  • Test tube stand
  • Two test tubes
  • Two iron nails
  • Measuring cylinder
  • Beaker
  • Sandpaper
  • Copper sulphate solution
  • Laboratory stands with clamp
  • Distilled water
  • Thread

Theory

  • As per the reactivity series, the more reactive metals displace the less reactive metals. When iron is compared with copper, it is placed above copper in activity series. Therefore the metals placed above are more reactive whereas the metals placed below are less reactive.
  • When iron nails are placed in CuSO4 iron displaces copper from copper sulphate to form ferrous sulphate. The iron nails get deposited with a brownish red substance of the copper metal. The reaction is as follows:

Metallic iron displaces copper ion from its salt is an example of a chemical displacement reaction. Metallic iron is converted to ferrous iron, the cupric ion is converted to metallic copper. The reaction is as follows:

Experimental Setup:

Image (instead of A and B use P and Q)

Procedure

  • Wash two test tube with distilled water and dry them.
  • Label the test tube as P and Q.
  • Add 20 mL of distilled water in the test tube and mix copper sulphate crystals in P.
  • Transfer 10 Ml of solution from P to Q.
  • Take two iron nails by cleaning them with sandpaper.
  • Take one iron nail and dip it in the in test tube P for 15 minutes.
  • Take another iron nail and dip it in the in test tube Q for 15 minutes.
  • Observe the intensity of the blue colour of before and after the experiment performed in test tube P and Q.
  • Record your results.

Observation

Observation
ExperimentBefore ExperimentAfter Experiment
Colour of BlueGreen
Colour of iron nailSilvery greyBrownish red coating

Result and Conclusion

From the above experiment 3 (C) we can conclude that the reaction occurred when iron nails were dipped in the copper sulphate solution for 15 minutes the colour of the solution changes to green and brownish red copper metal is deposited on the nail. Therefore, this is a displacement reaction.

Precautions to be Taken During the Experiment

  • Clean the iron nails by sandpaper before dipping in a copper sulphate solution.
  • Make dilute for the experiment otherwise, the colour change will not be seen in its concentrated form.
  • Use good quality boiling tube.

Questions

When Iron Nails Are Dipped in the Copper Sulphate Solution the Colour of the Solution Changes. Why?

Ans: Copper is less reactive when compared to iron. Therefore, iron has the ability to displace it from its salt solution.

What is the Basic Principle of this Experiment?

Ans: More reactive metals displace less reactive metals.

What is the Cause for Displacement Reaction?

Ans: Difference in reactivities of metals causes displacement reaction.

Can You Name the Metal That Deposits Reddish Brown Substance on the Iron Nails when Dipped in ?

Ans: Copper metal.

What Do You Mean by Reactivity Series of Metals?

Ans: Metals arranged in the decreasing order of their reactivities.

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