Question:
Thiosulphate reacts differently with iodine and bromine in the reactions given
below:
2S2O32- + I2 → S4O62- + 2I–
S2O32-+ 2Br2+ 5H2O → 2SO42- + 2Br–+ 10 H+
Which of the following statements justifies the above dual behaviour of
thiosulphate?
(i) Bromine is a stronger oxidant than iodine.
(ii) Bromine is a weaker oxidant than iodine.
(iii) Thiosulphate undergoes oxidation by bromine and reduction by iodine
in these reactions.
(iv) Bromine undergoes oxidation and iodine undergoes a reduction in these
reactions.
Solution:
Option (i) Bromine is a stronger oxidant than iodine is the answer.