Question

Account for the following:

Cu⁺ ion is unstable in aqueous solution.

Answer 1

Cu²⁺ is more stable than Cu⁺ in aqueous medium. Cu²⁺ has high hydration energy that compensates for the energy required to remove one electron from Cu⁺ to form Cu²⁺. So in aqueous medium, Cu⁺ gives Cu²⁺ and Cu.

Chemical reaction: \[\ce{2Cu^+_{( aq)} -> Cu^{2+}_{ (aq)} + Cu_{(s)}}\]