Identify the substance oxidised and reduced, oxidising agent and reducing agent for each of the following reactions
(a) `2AgBr(s)toC_(6)H_(6)O_(2)(aq)to2Ag(s)+2HBr(aq)+C_(6)H_(4)O_(2)(aq)`
(b) `HCHO(l)+2[Ag(NH_(3))_(2)]^(+)(aq)+3OH^(-)(aq)to2Ag(s)+HCOO^(-)(aq)+4NH_(3)(aq)+2H_(2)O(l)`
(c ) `HCHO(l)+2Cu^(2+)(aq)+5OH^(-)(aq)toCu_(2)O(s)+HCOO^(-)(aq)+3H_(2)O(l)`
(d) `N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l)`
`Pb(s)+PbO_(2)(s)+2H_(2)SO_(4)(aq)to2PbSO_(4)(s)+2H_(2)O(l)`

Explanation

`|{:(,"Substance oxidised","Substance reduced","Oxidising agent","Reducing agent"),(a.,C_(6)H_(6)O_(2)(aq),AgBr(s),AgBr(s),C_(6)H_(6)O_(2)(aq)),(b.,HCHO(aq),[Ag(NH_(3))_(2)]^(o+),[Ag(NH_(3))_(2)]^(o+),HCHO(aq)),(c.,HCHO(aq),Cu^(2+)(aq),Cu^(2+)(aq),HCHO(aq)),(d.,N_(2)H_(4)(l),H_(2)O_(2)(l),H_(2)O_(2)(l),N_(2)H_(4)(l)),(e.,Pb(s),PbO_(2)(s),PbO_(2)(s),Pb(s)):}|`