Question

Which of the following on reaction with thiosulphate ion gives sulphate ion and sulphur as is oxidized product?

• A. Chlorine
• B. Bromine
• C. Iodine
• D. Flurine

Answer 1

Answer: (A), (B)

The correct options are
A Chlorine
B Bromine

Thiosulfates react with halogen differently, which can be attributed to the decrease of oxidizing power down the halogen group :

$2S_2{O}_3^{2-}\left(aq\right)+I_2\left(aq\right)\to S_4{O}_6^{2-}\left(aq\right)+2I^{-}\left(aq\right)$

$S_2{O}_3^{2-}\left(aq\right)+4B{r}_2\left(aq\right)+5H_{2}O\left(I\right)\to 2S{O}_4^{2-}\left(aq\right)+8B{r}^{-}\left(aq\right)+10H^{+}\left(aq\right)$

$S_2{O}_3^{2-}\left(aq\right)+4C{I}_2\left(aq\right)+5H_{2}O\left(I\right)\to 2S{O}_4^{2-}\left(aq\right)+8C{l}^{-}\left(aq\right)+10H^{+}\left(aq\right)$