Chemistry: Types of Mixtures & Separation Techniques

A complete set of vocabulary flashcards based on the Year 7 Chemistry unit covering the definitions, characteristics, and components of mixtures and various separation techniques.

Mixture

A combination of two or more substances.

Pure substances

Materials that are not mixed with anything else, such as distilled water, helium, oxygen, and diamonds.

Characteristics

A feature or quality used by scientists to group mixtures based on what they are made from and how they behave.

Solution

A mixture where one substance is dissolved evenly throughout another; these are usually transparent.

Dissolved

When a substance spreads out into another liquid or gas and seems to disappear.

Transparent

A property of a substance meaning it is see-through, allowing light to shine through.

Suspension

A mixture where one substance is spread through another but does not dissolve, with heavier particles eventually settling to the bottom.

Sediment

Solids that settle to the bottom of a liquid over time.

Colloid

A suspension that does not separate over time and can be identified by the visibility of a light beam when shone through it.

Soluble

Substances that dissolve in a liquid, such as salt in water.

Insoluble

Substances that do not dissolve in a liquid, such as pepper in water.

Solute

The substance that is dissolving in a liquid to form a solution.

Solvent

The liquid in which the solute dissolves.

Dilute solution

A solution that only has a small amount of solute dissolved.

Concentrated solution

A solution that has a lot of solute dissolved.

Saturated

The state of a solution when no more solute will dissolve in the solvent.

Density

How tightly packed a substance is.

Volume

The amount of space an object takes up.

Decanting

A separation technique involving pouring out a liquid while leaving the sediment behind at the bottom.

Flotation

A separation technique used for substances less dense than the rest of the mixture, allowing them to be scooped from the top.

Evaporation (Process)

A process when a liquid slowly turns into a gas, usually at the surface, even when not boiling.

Evaporation (Technique)

Using different boiling points to separate a mixture by heating it until the liquid with the lower boiling point turns into a gas.

Boil

To turn into a gas throughout a liquid; for example, water boils at $100\,^{\circ}\text{C}$ and olive oil boils at $300\,^{\circ}\text{C}$.

Crystallisation

Heating a solution to boil the solvent, leaving the solute behind as a solid.

Filtration

The use of a filter to separate parts of a mixture by trapping bigger particles while letting small things and liquids pass through.

Filtrate

The substance or substances that pass through a filter.

Residue

The substance or substances that do not pass through a filter and are trapped.

Centrifugal force

The sensation of being pulled outwards when spinning, such as on a merry-go-round.

Centrifuging

Spinning a mixture very quickly to separate heavy parts from light parts by pulling the heavier parts outwards.

Centrifuge

A machine specifically used to spin mixtures around for separation.

Distillation

A separation technique that uses both evaporation and condensation to separate and collect substances from a liquid mixture.

Condensation

The process of a gas turning into a liquid.

Condenser

An apparatus that moves cold water around a tube containing vapor to cause the gas to condense back into a liquid.

Distillate

The liquid that is collected after it has been evaporated and then condensed back into liquid form.