NCERT Question 9 - Chapter 4 Class 8 - Materials : Metals And Non-Metals

What happens when

(a) Dilute sulphuric acid is poured on a copper plate?

(b) Iron nails are placed in copper sulphate solution?

    Write word equations of the reactions involved.

Answer

(a)

Here, we are mixing dilute acid with metal

Since less reactive metals do not react with acids. Copper will not react with dilute sulphuric acid.

Thus, no reaction will take place

Therefore,

Dilute Sulphuric Acid + Copper → No Reaction

H ₂ SO ₄ (dil) + Cu → No reaction

(b)

Here, displacement reaction will take place.

Iron(Fe) being more reactive than copper displaces copper from copper sulphate solution

Due to this reaction, the blue colour of copper sulphate becomes green color of Iron Sulphate.

And there is a red-brown decomposition of copper on the iron nail

Therefore,

Iron + Copper Sulphate → Iron Sulphate + Copper

Fe + CuSO ₄ → FeSO ₄ + Cu