18662 When \(S{n^{2 + }}\)changes to \(S{n^{4 + }}\)in a reaction
(a) \(S{n^{2 + }} \to S{n^{4 + }} + 2{e^ - }\). In this reaction \(S{n^{2 + }}\) change in \(S{n^{4 + }}\) it is called an oxidation reaction.
18663 Oxidation of thiosulphate \({S_2}O_3^{2 - }\) ion by iodine gives
(c) \(2{S_2}O_3^{2 - } + {I_2} \to {S_4}O_6^{2 - } + 2{I^ - }\).
18664 \(Z{n^{2 + }}_{(aq) } + 2e\, \to \,Zn_{(s)}.\) This is
(b)\(\mathop {Z{n_{(aq)}}}\limits^{2 + \,\,\,\,\,} + 2{e^ - } \to \mathop {Z{n_{(s)}}}\limits^{0\,\,\,\,} \) reduction.
18665 One gas bleaches the colour of flowers by reduction while the other by oxidation
(b) \(S{O_2}\) bleaches by reduction while chlorine bleaches colour of flowers by oxidation.