In the following redox reaction identify the oxidising agent and the reducing agent
`(i) H_(3)PO_(2)(aq)+2 HgCl_(2)(aq)+2H_(2)O(aq)rarrH_(3)PO_(4)(aq)+2 Hg(l)+4 HCI(aq)`
`(ii) O_(2)(g)+PtF_(6)(g)rarr O_(2)^(+)[PtF_(6)]^(-)(s)`

Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent. (a) P_(4)(s) + OH^(-) (aq) to PH_(3) (g) + HPO_(2)^(-)(aq) (b) N_(2)H_(4)(1) + ClO_(3)^(-) (aq) to NO(g) + Cl^(-)(g) (c) Cl_(2)O_(7)(g) + H_(2)O_(2)(aq) to ClO_(2)^(-)(aq) + O_(2) (g) + H^(+)

Identify the redox reaction out of the following reacitons and identify the oxidising and reducing agents in them. (a) 3HCl(aq)+HNO_(3)(aq)toCl_(2)(g)+NOCl(g)+2H_(2)O(l) (b) HgCl_(2)(aq)+2KI(aq)toHgI_(2)(s)+2KCl(aq) ( c) Fe_(2)O_(3)(s)+3CO(g)overset(Delta" ")(to)2Fe(s)+3CO_(2)(g) (d) PCl_(2)(l)+3H_(2)O(l)to3HCl(aq)+H_(2)PO_(3)(aq) (e) 4NH_(3)(aq)+3O_(2)(g)to2N_(2)(g)+6H_(2)O(g)

O_(3)(g)+I^(-)(aq)+H_(2)O(l) to

Identify oxidant and reductant in the reaction : I_(2) ("aq") + 2S_(2) O_(3)^(2-) ("aq") 2I^(-) ("aq") + S_(4) O_(6)^(2-) (aq) .