A smaller portion of a larger quantity of a substance.

When a substance's particles separate and spread throughout the particles of a solvent resulting in it no longer being seen.

Process of separating and quantifying the components of a sample to understand its nature and composition.

Water sample analysis: dissolved solids

Combined science

Separating mixtures (including formulations)

Solutions

Filtration

Crystallisation

Chromatography: paper

Interpreting chromatograms

Chromatography: separating a mixture of inks

Distillation: simple distillation

Distillation: separating a mixture of inks

Distillation: fractional distillation

Potable water

Wastewater treatment

Water sample analysis: pH

Water sample analysis: distillation

In the Making Salts unit, pupils will build on their understanding of separation techniques to learn about the process of making salts and writing balanced chemical equations.

In the Separation Techniques unit, pupils learned about various methods for separating mixtures, including filtration, evaporation, distillation, and chromatography.

This unit explores purification techniques, including filtration, crystallisation, and distillation. It explains formulations, uses chromatographic methods to identify pure and impure substances, and interprets chromatograms with Rf values. The emphasis is on accurate measurements.

Separating substances

Physical activity and equipment requiring safe use

What process is used to separate dissolved solids from a liquid?

By adding the mass of dissolved solids to the volume of the water sample.

By dividing the mass of dissolved solids by the volume of the water sample.

By multiplying the mass of dissolved solids by the volume of the water sample.

How can you calculate the concentration of dissolved solids in a water sample?

Why is it important to compare data from different water samples?

Collect and record the mass of the remaining dissolved solids.

Measure the volume of the evaporated solvent.

What should you do after heating the water sample in the evaporation process?

A 30 cm³ water sample contained 0.20 g of dissolved solids. What mass of dissolved solids is in a 5 cm³ sample?

Students heated 10 cm³ of a water sample in a 95.56 g evaporation dish, until dry. Which sample is pure water?

A mixture of two or more insoluble substances.

A mixture where the solute is completely dissolved in the solvent.

A mixture where the solute particles are visible.

Which of the following describes a solution?

To dissolve more solids into the solvent.

To separate dissolved solids by converting the solvent into a gas.

What is the main purpose of the evaporation process in water sample analysis?

What is the term for a substance that dissolves in a solvent to form a solution?

Which apparatus is used to accurately measure the volume of a liquid?

To allow the solute to settle at the bottom.

To ensure the solution is homogeneous and consistent.

Why is it important for solute particles to spread evenly throughout the solvent in a solution?

They separate and spread throughout the solvent particles.

What happens to the solute particles during the dissolution process?

Water sample analysis: dissolved solids

Lesson outcome

Content guidance