Consider the reactions :
(a) `H_(3)PO_(2) (aq) + 4 AgNO_(3) (aq) + 2 H_(2)O (1) to H_(3) PO_(4) ( aq) + 4 Ag(s) + 4HNO_(3)(aq)`
(b) `H_(3)PO_(2) (aq) + 2Cu SO_(4)(aq) + 2H_(2)O(1) to H_(3) PO_(4)(aq) + 2 Cu(s) + H_(2)SO_(4)(aq)`
(c) `C_(6)H_(5) CHO(1) + 2[Ag (NH_(3))_(2)]^(+) (aq) + 3 OH^(-) (aq) to C_(6)H_(5)COO^(-)(aq) + 2Ag(s) + 4NH_(3)(aq) + 2 H_(2)O(1)`
(d) `C_(6)H_(5)CHO(1) + 2Cu^(2+) (aq) + 5 OH^(-) (aq) to ` No change observed .
What inference do you draw about the behaviour of `Ag^(+)` and `Cu^(2+)` from these reactions ?

Explanation

These reactions suggest that `Ag^(+)` ion is a stronger oxidising agent than `Cu^(+)` ion. It is evident from the following facts.
(i) Reactions (a) and (b) suggest that both `Ag^(+)` and `Cu^(2+)` ions can oxidise `H_(3)PO_(3)` to `H_(3)PO_(4)`. Thus, both are oxidising agents.
(ii) Reaction (c) suggests that `[Ag(NH_(3))_(2)]^(+)` can oxidise `C_(6)H_(5)CHO` to `C_(6)H_(5)COOH`, but reaction (d) indicates that `Cu^(2+)` ions are unable to do so.
Hence, it may be concluded that although both `Ag^(+)` and `Cu^(2+)` act as oxidising agents, yet `Ag^(+)` is a stronger oxidising agent than `Cu^(2+)`.