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

Explanation

`to H_(3)PO_(2)` is a strong reducing agent hence it reduce. `Ag^(+)` to Ag and `Cu^(+2)` to Cu .
`to C_(6)H_(5)CHO` is also a reducing agent it just reduced.
`Ag^(+)` to Ag in tollen.s reagent but it does not reduced `Cu^(+2)` in alkaline solution .