Answer :
Oxidation-reduction reaction : It is a type of reaction in which oxidation and reduction reaction occur simultaneously.
Oxidation reaction : It is the reaction in which a substance looses its electrons. In the oxidation reaction, the oxidation state of an element increases.
Reduction reaction : It is the reaction in which a substance gains electrons. In the reduction reaction, the oxidation state of an element decreases.
(a) The balanced chemical reactions is,
\(2Na(s)+Br_2(l)\rightarrow 2NaBr(s)\)
Half reactions of oxidation and reduction are :
Oxidation : \(Na\rightarrow Na^{1+}+1e^-\)
Reduction : \(Br_2+2e^-\rightarrow 2Br^{1-}\)
From this we conclude that, 'Na' is oxidized and \('Br_2'\) is reduced in this reaction. The reducing agent is, 'Na' and oxidizing agent is, \('Br_2'\).
(b) The balanced chemical reactions is,
\(H_2(g)+Cl_2(g)\rightarrow 2HCl(g)\)
Half reactions of oxidation and reduction are :
Oxidation : \(H_2\rightarrow H^{1+}+1e^-\)
Reduction : \(Cl_2+2e^-\rightarrow 2Cl^{1-}\)
From this we conclude that, \('H_2'\) is oxidized and \('Cl_2'\) is reduced in this reaction. The reducing agent is, \('H_2'\) and oxidizing agent is, \('Cl_2'\).
(c) The balanced chemical reactions is,
\(2Li(s)+F_2(g)\rightarrow 2LiF(s)\)
Half reactions of oxidation and reduction are :
Oxidation : \(Li\rightarrow Li^{1+}+1e^-\)
Reduction : \(F_2+2e^-\rightarrow 2F^{1-}\)
From this we conclude that, 'Li' is oxidized and \('F_2'\) is reduced in this reaction. The reducing agent is, 'Li' and oxidizing agent is, \('F_2'\).
(d) The balanced chemical reactions is,
\(S(s)+Cl_2(g)\rightarrow SCl_2(g)\)
Half reactions of oxidation and reduction are :
Oxidation : \(S\rightarrow S^{2+}+2e^-\)
Reduction : \(Cl_2+2e^-\rightarrow 2Cl^{1-}\)
From this we conclude that, 'S' is oxidized and \('Cl_2'\) is reduced in this reaction. The reducing agent is, 'S' and oxidizing agent is, \('Cl_2'\).
(e) The balanced chemical reactions is,
\(N_2(g)+2O_2(g)\rightarrow 2NO_2(g)\)
Half reactions of oxidation and reduction are :
Oxidation : \(N_2\rightarrow N^{4+}+4e^-\)
Reduction : \(O_2+4e^-\rightarrow 2O^{2-}\)
From this we conclude that, \('N_2'\) is oxidized and \('O_2'\) is reduced in this reaction. The reducing agent is, \('N_2'\) and oxidizing agent is, \('O_2'\).
(f) The balanced chemical reactions is,
\(Mg(s)+Cu(NO_3)_2(aq)\rightarrow Mg(NO_3)_2(aq)+Cu(s)\)
Half reactions of oxidation and reduction are :
Oxidation : \(Mg\rightarrow Mg^{2+}+2e^-\)
Reduction : \(Cu^{2+}+2e^-\rightarrow Cu\)
From this we conclude that, \('Mg'\) is oxidized and \('Cu'\) is reduced in this reaction. The reducing agent is, 'Mg' and oxidizing agent is, 'Cu'.
