why is it when water is added to copper sulphate, the hydrogen does not displace the copper and form sulfuric acid?

hydrogen is more reactive than copper in the reactivity series

H2O + CuSO4 ---> H2SO4+ Cu?

Edited October 31, 20223 yr by observer1

No, CuSO4 dissociates to Cu(H2O)4 2+ ( blue colour) and SO4 2- ions, like all salts do if dissolved in water. NaCl => Na+ + Cl- as example.

And your equation is wrong.

H2O + CuSO4 ---> H2SO4+ Cu? You forget the oxygen from H2O

H2O + CuSO4 <--- H2SO4+ CuO is a reaction what can take place.

 

 

3 hours ago, observer1 said:

why is it when water is added to copper sulphate, the hydrogen does not displace the copper and form sulfuric acid?

hydrogen is more reactive than copper in the reactivity series

H2O + CuSO4 ---> H2SO4+ Cu?

Several reasons, but we can begin with entropy since you've overlooked a major consideration.

The copper ions (actually Cu(H₂O)₆ ²⁺) and sulphate ions have many more degrees of freedom floating around in the liquid phase than they do locked up in a solid crystalline phase - enough for that route to be thermodynamically favoured.

Dissolving copper sulphate in water is an exothermic process anyway, due to the additional ligand bonds formed in the hydrated complex ion, so the Gibbs Free Energy arrow is only ever going to point in one direction (at normal ambient conditions at least).

The extra bonding energy formed in such complex ions helps low reactivity elements (including platinum group metals) to leap up the reactivity index, so the latter is only a very approximate indicator, and often misleading if taken at face value.

Edited October 31, 20223 yr by sethoflagos
Clarification

4 hours ago, observer1 said:

H₂O + CuSO₄ ---> H₂SO₄+ Cu?

because the correct reaction is
H₂ + CuSO₄ ---> H₂SO₄+ Cu?

And, in principle, that works.
In practice you ned a catalyst like platinum.

Edited October 31, 20223 yr by John Cuthber

Yeah that is the correction of the observers1 question.

Edited October 31, 20223 yr by chenbeier