Question

Give an example of a liquid in liquid solution.
[A] Alcohol in water
[B] Milk
[C] Smoke
[D] None of these

Answer 1

HINT: A solution is a mixture of solutes in a solvent. To answer this question, look for the mixture of miscible liquids. Remember that milk has tiny globules of protein present in it. Use this to find the correct answer.

COMPLETE STEP BY STEP SOLUTION: To solve this question, firstly let us discuss what a solution is.
In chemistry, we define a solution as a homogeneous mixture of two or more solutes in a solvent. Solute is the substance which dissolves to form a homogeneous solution. Solvent is the liquid in which the solute is dissolving.
Generally, we describe a solution as a liquid. But, there can be gaseous solutions too. If the solvent is a gas and other gases are dissolved in it then it is a gaseous solution.
In the question we have been asked for an example of a liquid in liquid solution. Therefore, option [C] smoke cannot be the correct answer.
Then we have milk. Milk is a colloidal dispersion of fat in water. There are tiny globules of protein present in milk which we can see if examined under a microscope. Fat and water cannot be mixed together to form a solution and thus two immiscible phases of liquids are visible. Therefore, milk is not a liquid in liquid solution.
And lastly we have alcohol in water. Water and alcohol are miscible liquids i.e. they will appear in a single phase and completely mix with each other to give us a solution. So this is an example of a liquid in liquid mixture.

Therefore, the correct answer is option [A] alcohol in water

NOTE: A mixture can be homogeneous or heterogeneous. We can define a homogeneous mixture as a mixture where the composition of the solute is the same throughout the solution. Example of a homogeneous mixture is sugar dissolved in water, paint, alcohol etc. We can define a heterogeneous mixture as the mixture where the composition of the solvent is not the same throughout the solution.
Example of a heterogeneous mixture is oil in water as they do not mix and the solution is not uniform.