The electronic configuration of Cu(II) is 3d9 whereas that of Cu(I) is 3d10, the correct statement about the aqueous solution of  Cu(II) and Cu(I) among the following is-

1. Cu(II) is more stable
2. Cu(II) is less stable
3. Cu(I) and Cu(II) are equally stable
4. Stability of Cu(I) and Cu(II) depends on the nature of copper salts



Hint: Cu(II) has high hydration energy
 
Cu(II) is more stable than Cu(I). As it is known that, Cu(I) has 3d10 stable configuration while Cu(II) has  3d9 configuration. But Cu(II) is more stable due to greater effective nuclear charge of Cu(II)i.e., it hold 17 electrons instead of 18 in Cu(I). Cu(II) has high hydration energy than Cu(I) hence, Cu(II) is more stable than Cu(I).