Question

H2 gas is evolved in the chemical reaction between H2SO4 and Zn.If we pleace Cu in the place of Zn,what will happen?why?

Answer 1

Copper does not react easily, hence dilute dilute H2SO4 will have no reaction.
But concentrated sulphuric acid will react and sulphur dioxide and water are evolved, and copper sulphate is formed.
Cu + 2H2SO4 = CuSO4 + SO2 + 2H2O
copper + sulphuric acid = copper sulphate + sulphur dioxide + water

Answer 2

Zinc is more reactive than Hydrogen.
Hence, it displaces hydrogen from sulfuric acid and hydrogen gasi is liberated.

Zn + H2SO4 --------> ZnSO4 + H2
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But copper is less reactive than hydrogen.
Hence it cannot displace hydrogen from sulfuric acid.So no reaction will occur

Cu + H2SO4 --------> No reaction.