Which one of the following is not a solution?
Alloy
Milk
Air
Sugar
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-1 – 2022
A solution is a homogeneous mixture of two or more substances. Among the given options, milk is a heterogeneous mixture (specifically a colloid).
An alloy is a homogeneous mixture of metals or a metal and a non-metal (e.g., brass, steel), so it is a solution (solid solution). Air is a homogeneous mixture of gases (primarily nitrogen and oxygen), so it is a solution (gaseous solution). Milk contains dispersed particles of fat and protein which are not uniformly distributed at the microscopic level, making it a heterogeneous mixture (colloid). Sugar itself is a pure substance (compound), but if dissolved in water, it forms a homogeneous mixture (sugar solution). However, given the options as listed, Milk is the only one that is definitively not a solution.