Question

Milk is a:

• A. True solution
• B. Colloidal solution
• C. Suspension
• D. Saturated solution

Hint:

Milk is a colloidal solution, where fat droplets are suspended in water, and it shows the Tyndall effect.

Answer 1

The Correct Option is B

Compare milk with a glass of clear salt water on one side and a glass of muddy water on the other.

1. True solution: salt water stays perfectly transparent. Milk is opaque and white, so it clearly is not behaving like salt water.
2. Colloidal solution: milk's fat globules and proteins are spread evenly through the water and stay that way, similar to how other food colloids like cream behave. This matches milk closely.
3. Suspension: muddy water separates into mud and clear water if left standing. Milk does not separate like this under ordinary storage.
4. Saturated solution: that term applies to a dissolved solute at its limit, not to the fat and protein particles floating through milk.

Milk behaves like neither clear salt water nor settling muddy water, but like an evenly dispersed colloid, so the correct answer is colloidal solution.

Answer 2

Each option names a different category of mixture. Match milk's known composition, fat globules and protein suspended in water, against what defines each category.

1. True solution: defined by a solute dissolved down to individual molecules or ions. Milk's fat globules are far bigger than that, so this definition does not apply.
2. Colloidal solution: defined by particles too small to settle but large enough to scatter light and stay permanently dispersed. Milk's fat and protein particles fit this definition.
3. Suspension: defined by particles large enough to settle under gravity over time. Milk's particles are too small for that.
4. Saturated solution: defined purely by the amount of dissolved solute relative to a solubility limit, which has nothing to do with milk's fat globules.

Milk's particles fit the definition of a colloid, so the correct answer is colloidal solution.