Question

add nail i. CuSO4 solution.The colour of CuSO4 disappears why

Answer 1

because cu is less reactive

Answer 2

The color of copper sulfate (CuSO₄) solution changes when a nail is added to it because iron is more reactive than copper. The blue color changes to green color.

When an iron nail is dipped in a copper sulfate solution, the very reactive iron displaces the copper from its solution and forms green colored iron sulfate or Ferrous sulfate (FeSO₄).

Fe (solid) + CuSO₄ → FeSO₄ (aqueous) + Cu (s)

With this displacement reaction, the blue colored Copper sulfate solution changes to green color.