Previous Year Question
Milk of Magnesia is which type of colloid?
Correct Answer: D
Detailed Solution
In school-level classification of colloids, a sol has a solid dispersed phase and a liquid dispersion medium. In Milk of Magnesia, magnesium hydroxide, Mg(OH)₂, is dispersed in water; therefore, among the given options, it is classified as a sol.
Its composition can be understood as:
Dispersed substance = Mg(OH)₂ (solid)
Dispersion medium = Water (liquid)
Important fact: In pharmaceutical terminology, Milk of Magnesia is more precisely described as a magnesium hydroxide suspension. DailyMed of the U.S. National Library of Medicine also labels Milk of Magnesia as a “magnesium hydroxide suspension.” Thus, the term “colloid” in this question follows school-level classification; among the given options, the expected answer is Sol.