On addition of conc. $\mathrm{H}_2 \mathrm{SO}_4$ to a chloride salt, colourless fumes are evolved but in case of iodide salt, violet

• A

  $\mathrm{H}_2 \mathrm{SO}_4$ reduces HI to $I_2$
• B

  HI is of violet colour
• Correct answer
  C

  HI gets oxidised to $\mathrm{I}_2$
• D

  HI changes to $\mathrm{HIO}_3$

Hence, the correct answer is option: 'C'.