Identify the redox reactions out of the following reactions and identify the oxidising and reducing agents in them.

(i) 3HCI(aq) + HNO3 (aq) CI2(g) + NOCI (g) + 2H2O(l)


(ii) HgCI2 (aq) + 2KI (aq) HgI2 (s) + 2KCI (aq)


(iii) Fe2O3 (s) + 3CO(g) 2Fe (s) + 3CO2(g)


(iv) PCI3 (I) + 3H2O (I) 3HCI (aq) + H3 Po3 (aq)


(v) 4NH3 + 3O2 (g) 2N2 (g) + 6H2 O (g)



Option (i)


Cl oxidizes from -1 to 0 and Nitrogen reduced from +5 to +3. Thus as Cl oxidizes it acts as reducing agent and nitric acid acts as an oxidizing agent.


Reducing agent: HCl


Oxidizing agent: HNO3


Option (ii)


This reaction is an example of displacement reaction, and none of the components undergo oxidation or reduction, as the oxidation states oh Hg, Cl, K, & I are same in both reactants and products.


Option (iii)



Oxidising agent: Fe2O3


Reducing agent: CO


Option (iv)



Oxidising agent: O2


Reducing agent: NH3


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