medium difficulty5 min

Solutions and their Components

A solution is a homogeneous mixture of solute and solvent; the solute is the substance dissolved, and the solvent is the substance present in larger amount that dissolves it.

In one line: Solute is put in; solvent lets it spread.

Practice This Concept

Understand it

In a salt solution, salt is the solute and water is the solvent. The solvent forms the main medium, while the solute spreads uniformly in it. True solutions do not show particles to the naked eye and do not scatter light strongly.

Example

In lemonade, sugar and lemon juice are solutes, while water is the solvent if it is present in the largest amount.

Rule to remember

Rule: solute is dissolved; solvent usually has larger amount and acts as the dissolving medium.

See it worked out

Follow the example line by line, then use the same method on new questions.

Worked example

In 20 mL alcohol mixed with 80 mL water, water is generally the solvent because it is present in larger amount, and alcohol is the solute.

Method you can reuse

1Read the quantities.
2Identify the component present in larger amount as solvent in ordinary school-level cases.
3Identify the dissolved component as solute.
4Confirm that the mixture is uniform.

Visual tip

A particle diagram may show solute particles evenly spread among solvent particles.

Check yourself

Answer the question in your head before opening the answer.

Try it yourself

In a solution made by dissolving 5 g salt in 100 g water, which component is the solvent and why?

Think first, then show answer

Water is the solvent because it is present in larger amount and dissolves the salt to form a uniform solution.

Common wrong answer

Saying every liquid is solvent.

Why it loses marks: A liquid present in smaller amount can act as solute.

Don't mix this up

Students sometimes identify the solid as solute and liquid as solvent always. In some solutions, both components may be liquids, so relative amount matters.

Exam tip

Mention solute, solvent, and uniform distribution when explaining a solution.