Acidified solutions of sodium thiosulphate are unstable because in thi...
Explanation:
Sodium thiosulphate is a salt of thiosulphuric acid, which is a polythionic acid. Polythionic acids are unstable in acidified solutions due to the presence of multiple sulphur atoms and different oxidation states of sulphur.
The instability of acidified solutions of sodium thiosulphate is due to the following reasons:
- Different Oxidation States: Thiosulphate contains two sulphur atoms in different oxidation states, i.e., 6 and -2. This creates a potential for redox reactions, and the presence of acid further enhances the instability of the oxidation states.
- Disproportionation: In acidic solutions, thiosulphate undergoes disproportionation, which means that it undergoes both oxidation and reduction reactions. This leads to the formation of sulphur dioxide, sulphur, and sulphate ions. This reaction is also responsible for the bleaching property of sodium thiosulphate.
- Acid Hydrolysis: Acid hydrolysis of thiosulphate leads to the formation of sulphuric acid and sulphur dioxide. This reaction further enhances the instability of thiosulphate in acidic solutions.
Hence, the correct answer is option B, i.e., the two sulphur atoms are at different oxidation states of 6 and -2.
Acidified solutions of sodium thiosulphate are unstable because in thi...
Option B is right
Na2So2O3+Hcl that gives 2 Nacl+So2+S+H2O sodium thiosulphate, in the presence of dilute acids decomposes to give So2 And S that's why option B is right
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