Page 130 - Knowledge Organiser Yr7 24-25

Knowledge Base: Science 7.5 Mixtures Year 7
4. Filtration and Crystallisation
4.1
What is a mixture?
A substance containing different substances that are not chemically joined to each other and which can be separated.
4.2
How could you separate an insoluble solid from a liquid?
Filtration.
4.3
What equipment would you need to carry out filtration?
Filter paper, filter funnel, conical flask.
6. Chromatography
6.1
What is the purpose of chromatography?
A method to separate mixtures of soluble substances.
6.2
What examples of substances can be separated using chromatography?
Food colourings, inks, dyes or plant pigments.
6.3
What is a chromatogram used for?
To identify the soluble substances in a mixture.
6.4
In chromatography, what is the purpose of the water?
To act as the solvent.
6.5
What causes different soluble substances to move different distances during chromatography?
Due to differences in their solubility (their ability to dissolve). The further
the distance, the greater the solubility.
6.6
Why do we draw the start line on a chromatogram in pencil?
The pencil line is insoluble in water.
6.7
Draw a diagram to show chromatography:
4.4 What is the solid left behind in the filter paper called? Residue.
4.5
What is the name of the liquid collected after filtration has taken place?
Filtrate.
4.6
How do we separate a soluble solid from a solution?
Evaporation.
4.7
What equipment would you need
to carry out the evaporation process?
Evaporating basin, Bunsen burner, tripod.
4.8
What is crystallisation?
The process of producing crystals from a solution by evaporating the solvent.
5. Distillation
5.1
What process would you use to separate a solvent from a solution?
Distillation .
5.2
How is distillation carried out?
The solution is heated, causing the solvent to evaporate and turn into a gas. The gas is cooled and condenses back into a liquid which is collected.
5.3
What equipment is used for distillation?
Round bottomed flask, Bunsen burner and Liebig condenser.
5.4
What is left in the round bottomed flask after distillation?
The solute.
130