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)`

Explanation

(i) writing the O.N on each atom above its symbol we hve
here the O.N of CI increase from -1 in HCI to 0 in `CI_(2)` therefore `CI^(-)` is oxidised and hence HCI acts as the reducing agent
The O.N of N decreases from +5 in `HNO_(3)` to +3 in NOCI therefore `HNO_(3)` acts as the oxidising agent thus reaction (i) is a redox rection ltbRgt (ii) writing the O.N of each atom abvoe its symbol we have
therefore the O.N of none of the atoms undergo a change therefore raction (ii) is not a redox reaction
(iii) here O.N of fe decreases from +3 in `Fe_(2)O_(3)` to O in Fe therefore `Fe_(2)O_(3)` acts as an oxidising agent further O.N of C increases from +2 in CO to +4 `CO_(2)` therefore reaction (iv) is not a redox reaction (v) writing the O.N of each atom above its symbol we have
Here O.N of N increase from -3 to o in `N_(2)` therefore `NH_(3)` acts as a an reducing agent further O.N of O decrease from 0 in `O_(2)` to -2 in `H_(2)O` therefore `O_(2)` acts as a oxidsing agent thus reaction (v) is redox reaction