Question

When $C{l}_2$ water is added to an aqueous solution of potassium halide in the presence of chloroform, a violet color is obtained. On adding more of $C{l}_2$ water, the violet color disappears and a colorless solution is obtained. This test confirms the presence of the following in aqueous solution :

• A. iodide.
• B. bromide.
• C. chloride.
• D. iodide and bromide.

Answer 1

The correct option is A iodide.

When this reagent is added dropwise to a solution of an iodide, free iodine is liberated, which colours the solution brown and on shaking with $C{S}_2,CHC{l}_3$ or $CC{l}_4$ it dissolves in organic layer forming a violet solution, which settles below the aqueous layer.

$2KI+C{l}_2\to I_2+2KCl$

$I_2+Chloroform\to$ Violet solution