Q. The solubility of iodine in water increases in presence of
A) Chloroform
B) Alcohol
C) Potassium iodide
D) Sodium hydroxide
Explanation
(c)
Iodine has the least affinity for water and is only slightly soluble in it. However, it dissolves in 10% aqueous solution of $KI$ due to the formation of a complex ion $ie,\ I_{3}^{-}$
$I_{2} + KI \rightleftharpoons KI_{3}$
or $I_{2} + I^{-} \rightleftharpoons I_{3}^{-}$
(Complex ion)
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.