Acidified solutions of sodium thiosulphate are unstable because in thiosulphate

Options

A. The two sulphur atoms are at unstable oxidation state of +2
B. The two sulphur atoms are at different oxidation state of +6 and -2
C. The S-S bonds are unstable
D. Thio compounds contain S in oxidation state of zero.

Answer

B

Explanation

`Na_2S_2O_3+ HCI to 2NaCl + SO_2 +S+H_2O`
Sod. thiosulphate, in the presence of dil. acids decomposes to give `SO_2` and S. This is because S is in +6 and -2 oxidation state in `S_2O_3^(2-)`
`.^(-)O-undersetunderset(O)(||)oversetoverset(S)(||)S-O^-`
Structure of `S_2O_3^(2-)` ion