8. Identify and describe methods used to separate suspensions, including decanting, sieving, centrifugation and filtration.

Separation Technique(Suspensions) - Description

Decanting - Pouring off top layer of settled suspension

Sieving - Using sieve with small-medium sized holes to separate different sized particles in suspension

Centrifugation - Using device to quickly spin an unsettled suspension to settle it

Filtration - Using a filter with very fine pores to separate different sized substances in a mixture

9. Identify the limitations and benefits of decanting, sieving, centrifugation and filtration.

Separation Technique(Suspension) - Limitations - Benefits

Decanting - Can only be used on settled suspensions - Simple and easy

Sieving - Can only be used on different sized substances where only one can fit in holes - Simple and easy

Centrifugation - Hard and lengthy process, can only be used on unsettled suspensions - One of few ways to settle out suspension that may never settle

Filtration - Can only be used on different sized substances where only one can fit in holes - Simple and easy, useful when substance is trapped in another

10. Identify everyday examples where decanting, sieving, filtration and centrifugation can be used.

Separation Technique(Suspensions) - Examples

Decanting

Pour off water from vegetables
Pour wine into container, leaving behind sediment

Sieving

Sieve used to ensure only rocks of correct size go in crusher
To grade soil by size for classification

Filtration

Separate coffee grounds from filter coffee
Separate dust from air using mask filter

Centrifugation

Spin cycle of washing machine
Salad spinners to dry washed lettuce

11. Identify and describe methods used to separate solutions, including evaporation, condensation, crystallisation and distillation.

Separation Technique(Solutions) - Description

Evaporation

Heat is used to evaporate liquid solvent, leaving behind solute

Condensation

After solvent is evaporated, it can be condensed so the solvent isn’t lost

Crystallisation

As solvent evaporates, solution becomes so concentrated that solute forms crystals

Distillation

Evaporation used to separate solvent from solute, then retrieved using condensation

12. Identify everyday examples where evaporation and distillation can be used.

Separation Technique(Solutions) - Examples

Evaporation

Clothes on drying rack dry from evaporation
After swimming in sea, water on skin evaporates, leaving salt behind

Distillation

Separating crude oil into petrol, diesel etc.
Water cycle(water from sources evaporates, condenses into clouds)

13. Identify and describe methods used to separate solids, including centrifugation, electrostatic, sieving and magnetic attraction.

Separation Technique(Solids) Description

Centrifugation

Suspension is spun around at high speeds, settling out solid in liquid

Electrostatic

Particles of different polarity are separated in a solid

Sieving

Two solids are put through a sieve - one fits in holes, the other doesn’t

Magnetic Attraction

Magnet attracts magnetic substance away from non-magnetic substances

14. Identify some examples where chromatography can be used.

Chromatography Examples

Water dissolves dye in ink, and carries different colours up the paper
Can be used to find out what is in oil and gas
Can be used to find drugs in urine

15. Using examples, describe the separation process of adsorption.

Adsorption - components which stick to surface, but not go in surface(adsorbate) onto a solid surface (adsorbent), separating mixture.

Examples

When water molecules adsorb to windows, making it misty
When paint adsorbs to a painting surface

	Created by Sean Sacriz almost 6 years ago

HSC Science (Mixtures) Note on Mixtures Outcomes, created by Sean Sacriz on 03/10/2018.