Question

Hydrogen iodide is not produced by the reaction of concentrated sulphuric acid with Sodium chloride. Why?​

Answer 1

Answer:

Concentrated sulphuric acid isn't a strong enough oxidising agent to oxidise fluoride or chloride ions. In those cases, all you get produced are the steamy fumes of the hydrogen halide - hydrogen fluoride or hydrogen chloride.

Iodide ions are stronger reducing agents than bromide ions are. They are oxidised to iodine by the concentrated sulphuric acid.



The reduction of the sulphuric acid is more complicated than before. The iodide ions are powerful enough reducing agents to reduce it