Question

A clean iron nail was placed in a test tube containing copper sulphate solution. After some time, the colour of the solution changed from blue to green.

a. Write the chemical equation involved in it.

b. Name the type of reaction that takes place.

c. Why does the colour of the solution change from blue to green?

Answer 1

Answer:

When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.

Reaction

CuSO4 (aq) + Fe (s) → FeSO4 (aq) + Cu (s)

In this reaction following two processes take place:

Cu²⁺ + 2e = Cu⁰ (re­duc­tion process, Cu²⁺ is the ox­i­dizing agent)

Fe⁰ – 2e = Fe²⁺ (ox­i­da­tion process, Fe⁰ is the re­duc­ing agent)