separation techniques

Question 1

Hand, Sieve or Magnet:

Answer 1

• Used to separate 2 or more solid substances that
are of different size
• Substances can be separated by hand, or the use
of a sieve or magnet
• Ex: Separating Smarties by hand; using a sieve to
separate nickles from sand; using a magnet to
separate nails from saw dust

Question 2

Filtration:

Answer 2

• Used to separate liquids from solids(mechanical
mixtures involving liquids and solids)
• Cannot be used to separate DISSOLVED solids from
liquids
• Can use filter paper, filter or strainer

Question 3

Evaporation:

Answer 3

• Used for separating solid dissolved in a liquid
solution
• The solid will be kept the liquid will be discarded
• Allows the liquid in a solid‐in‐liquid solution to
evaporate or to be boiled out leaving the solid
behind

Question 4

Distillation:

Answer 4

• Use to separate 2 liquids that are dissolved together
• Both liquids will be kept
• The liquids present will have different boiling temps
• The solution is heated and the liquid with the lowest
boiling point will boil off first
‐ Its evaporate will be collected
• Distilate: component that boils off and is collected
elsewhere

Question 5

Solvent Extraction:

Answer 5

• There are 2 types:
A) Extraction of one solid from a
mixture of solids
‐ Uses a solvent that dissolves one of the solids
present but leaves other undissolved
B) Extraction of a dissolved liquid or
solid from a liquid solution
‐ Apply the same concept as before
‐ Add a solvent that is miscible with only one of
the liquids and immiscible with the other

Question 6

Gravity Separation:

Answer 6

• Separating a mechnical
mixture based on the densities
of the components involved
• Most dense component will
settle to the bottom
• Least dense will be on the top

Question 7

Chromatography:

Answer 7

• Used to separate a mixture of different coloured
solids in a solid or a liquid
• Separates based on the principal that certain
chemicals will travel further in a solvent than others
• 2 types:
a) Paper
b) Gas

Question 8

when would you use: hand separation?

Answer 8

• Solid in solid: large chunks present among other solids

- Solid in liquid: a few large pieces of solid are present in the liquid

Question 9

when would you use: solvent extraction?

Answer 9

-Solid in solid: one solid dissolves in a particular solvent

Question 10

when would you use: gravity separation?

Answer 10

• Solid in solid: density of desired solids is much different from the density of other solids
• Solid in liquid: solid particles are present in a small amount of liquid

Question 11

when would you use: filtration?

Answer 11

-Solid in liquid: solid particles are present in a large amount of liquid

Question 12

when would you use: chromatography?

Answer 12

-Solid in solid: solids are coloured, present in small amounts and are soluble in some solvent or mixture of solvents

Question 13

what techniques would you use for solids in solids?

Answer 13

• hand separation
• solvent extraction
• gravity separation
• chromatography

Question 14

what techniques would you use for solids in liquids?

Answer 14

• hand separation
• gravity separation
• filtration