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Chapter 4 Exploring diversity of matter (Separation Techniques) - Coggle…
Chapter 4 Exploring diversity of matter (Separation Techniques)
What is it for?
separating mixtures
solutions
suspensions
Types of separating techniques
Filtration
What is it for?
separating insoluble solid from suspension
How?
Residue (insoluble solid) will be collected on the filter paper.
Filtrate will be collected in conical flask (liquid passed through the filter paper).
Pour the mixture through a filter funnel with filter paper.
Distillation
How?
Vapour (gas) will be condensed (in the condenser) to be collected as
distillate
.
Solution will be boiled in a round bottom flask (at the boiling point - pure substances have fixed/single boiling point)
types of distillation
simple distillation (one solvent from solution)
fractional distillation (different liquids in one solution have different boiling points)
What is it for?
separating solvent (pure liquid) from solution
Magnetic attraction
What is it for?
separating magnetic materials from non-magnetic ones.
How?
Use a magnet/magnetic material
Paper chromatography
How?
A drop of sample is placed in the starting line (in pencil) drawn on a filter paper (chromatogram)
Filter paper will be dipped into a solvent (e.g. water). Solvent will be below the starting line.
Reading the chromatogram
Sample only separated as
one dot
= pure substance
Sample separated into
multiple dots
= mixture (travelled same distance = similar substance)
More soluble, substance will travel further from starting line
What is it for?
Separates coloured substance in a mixture (with
different solubilites
) for
identification
when compared to a sample
Evaporation
How?
Heat the water/solvent to obtain the solid (left behind)
types of evaporation
crystallisation (evaporate most of the water with indirect heating)
evaporation to dryness (evaporate all of the water with direct heating) e.g salt from seawater
What is it for?
separating soluble/dissolved solid (solute) from the solution
Four Taps of Singapore
Imported water
Imports water from Johor, Malaysia (Linggiu River mainly)
water is chemically treated, filtered and disinfected to be safe for consumption (within WHO's drinking water guildlines)
Desalinated water
In Singapore, separation of pure water from seawater is done by reverse osmosis (not distillation - needs alot of energy [high cost]
Reversed osmosis: a membrane is used to separate water from the salt in seawater with force (holes in the membrane only allow water particles to pass through but not larger salt particles.)
Rainwater from local catchments
17 reservoirs for storage (channelled from drains, canals, river and stormwater)
water is chemically treated, filtered and disinfected to be safe for consumption (within WHO's drinking water guildlines)
NEWater
produced from treated used water that is further purified using advanced membrane technologies such as reverse osmosis
water is exposed to UV radiation for disinfection as added safety measure.
currently meets 30%of Singapore's water needs (mainly for non-drinking industrial uses)