The process of separating an insoluble substance from a liquid using a filter.

Paper with tiny holes, placed inside the filter funnel to separate an insoluble solid from a liquid.

A cone-shaped tool with a tube, placed in the top of a conical flask during filtration.

The insoluble solid that remains in the filter paper.

The liquid that passes through the filter paper, separating from the insoluble solid.

Separating an insoluble solid from a liquid

Science

Separating a soluble solid from a liquid

Separating pure salt from dirty rock salt

Separating liquids

Simple distillation

Distillation: practical

Chromatography

In the Understanding Chemical Reactions unit, pupils will build on their understanding of physical changes to learn how atoms rearrange to form new substances during chemical reactions (chemical changes).

In the key stage 2 Properties, changes and separating materials unit, pupils learnt about mixtures, including solutions, and separation techniques including filtering and evaporation.

This unit covers techniques for separating mixtures, including filtration, evaporation, distillation, and chromatography, as well as identifying pure substances. Conduct experiments safely, record observations, evaluate methods, and suggest improvements.

Separation techniques

A solute is a substance that has dissolved into a solvent.

A solvent is a liquid into which a solute dissolves.

Occurs when a substance's particles are in the liquid state at its surface with enough energy to change to the gas state and mix with air.

A process that forms solid crystals from a saturated solution by evaporating the solvent.

A crystal is a solid whose particles are arranged in a highly ordered, repeating pattern.

A process or method used to isolate a substance from a mixture, usually to obtain a pure sample of it.

A property is a feature or characteristic of a substance that can be used to classify it, or describe how it behaves.

When a substance dissolves in a liquid it is described as soluble in that liquid.

An insoluble substance is one that will not dissolve in a particular solvent.

Density is a measurement of mass per unit volume; how tightly packed a substance's particles are in a particular space.

The boiling point of a substance is the temperature at which it changes from a liquid state to a gas state.

Liquids that are not soluble in another liquid are described as immiscible in that liquid.

Liquids that dissolve in another liquid are described as miscible in that liquid.

Decanting is a process of pouring off the top layer in a mixture of immiscible liquids, or a liquid and insoluble solid.

Distillation is a separation technique that uses boiling and condensation to remove and isolate a liquid part of a mixture.

Condensation is the process by which a substance in the gas state is cooled and changes to a liquid state.

A delivery tube is a thin tube used to transfer (i.e. "deliver") a substance (usually in the gas state) from one container to another.

A condenser is a piece of apparatus composed of a tube surrounded by a cold layer, usually cold water.

The liquid that is condensed from the gas state during distillation is called the distillate.

Distillation is a separation technique that uses boiling and condensation to remove and isolate the liquid part of a mixture.

A fraction is a part of something whole (e.g. a slice of cake).

Boiling occurs when a substance in the liquid state is heated and changes to the gas state with gas bubbles formed.

When a substance dissolves in a liquid, it is described as soluble in that liquid.

Chromatography is a technique that separates a mixture into its different parts and the results can be analysed.

A chromatogram is the resultant pattern on the stationary phase after chromatography has been carried out.

To compare is to look for similarities and/or differences between two objects or ideas.

Separation techniques

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