Among the following pairs of ions the lower oxidation state in aqueous solution is more stable than the other in

In which of the following pairs of ions, the higher oxidation state in aqueous solution is more stable than the other? I. TI^(+), TI^(3+) II. Cu^(+),Cu^(2+) III. Cr^(2+),Cr^(3+) IV. V^(2+),V^4+

Which one of the following ions is the most stable in aqueous solutions ?

+2 oxidation state of lead is more stable than +4 , because of

Which of the following ions is most stable in aqueous solution ?

The + 1 oxidation state of thallium is more stable than its + 3 state. Why ?