On addition of conc. `H_(2)SO_(4)` to a chloride salt, colourless fumes are evolved but in case of iodide salt, violet fumes come out. This is because

Options

A. `H_(2)SO_(4)` reduces HI to `I_(2)`
B. HI is of violet colour
C. HI gets oxidised to `I_(2)`
D. HI changes to `HIO_(3)`

Answer

C

Explanation

Hydrogen iodide (HI) is more stronger oxidising agent than `H_(2)SO_(4)` . So , it reduces `H_(2)SO_(4)` to `SO_(2)` and itself oxidises to `I_(2)`. Is violet hence in adding conc. `H_(2)SO_(4)` to HI, it gets oxidised to `I_(2)`.
`H_(2)SO_(4)+2HItounderset(("Violet colour"))(SO_(2)+I_(2)+2H_(2)O)`