Question

What is the qualitative significance of zinc reacts with sulphuric acid to give zinc sulphate and hydrogen

Answer 1

If the granulated zinc pieces are shiny then the reaction in test-tube 1 is slow. The reaction may be faster if the zinc is not very pure. Bubbles of hydrogen form on the surface of the zinc. The reaction is:

Zinc + Sulfuric acid → Zinc sulfate + Hydrogen

Zn(s) + H2SO4(aq)→ ZnSO4(aq) + H2(g)

In test-tube 2, copper is the catalyst for the reaction, and the reaction should be faster than in test-tube 1, but may not be as fast as test-tube 3.

In test-tube 3, zinc displaces copper from the copper sulfate solution and the surface of the zinc goes black. The displaced copper metal then acts as a catalyst for the reaction.

Zinc + Copper sulfate → Zinc sulfate + Copper

Zn(s) + CuSO4 (aq) → ZnSO4(aq) + Cu(s)