Q: How are mixtures separated?
A: Using differences in physical properties
Q: Why can mixtures be separated physically but compounds cannot?
Mixtures = no chemical bonds → physical separation works
Compounds = chemical bonds → need chemical reactions
Key physical properties used in separation
A:
Particle size
Density
Solubility
Boiling point
Magnetism
Electrical properties
What is filtration?
Separates an insoluble solid from a liquid (particle size) (solubility)
Key terms in filtration
Filtrate = liquid that passes through
Residue = solid left behind
Q: What is sieving?
A: Separation based on difference in particle size
Q: What is centrifugation?
A: Spinning process that separates particles by size and density, simulates gravity, forcing heavier ones outward. (particle size) (density)
Dense ones move further
Q: Limitation of particle-size methods
A: Cannot separate dissolved substances
Q: What is decanting?
A: Pouring off the less dense liquid from a mixture. (density)
Q: What is a separating funnel?
A: Pear shaped device used to separate immiscible liquids based on density. (density)
immiscible
of liquids) not forming a homogeneous mixture when mixed.
Q: Key rule for density separation
Less dense → top
More dense → bottom
Real-world example of density separation
Oil and water separation
How does magnetic separation work?
A magnet removes magnetic materials from non-magnetic ones. (M&E)
Example of magnetic separation
Recycling / waste sorting
What is electrostatic separation?
Uses charge differences to separate particles. (M&E)
Q: Real-world example of electrostatic separation
A: Removing dust from industrial chimney emissions
Q: What is solubility-based separation?
A: Separating substances based on whether they dissolve or not
Q: How do you separate sand and salt?
Add water → salt dissolves
Filter → sand removed
Evaporate → salt recovered
Q: What is evaporation?
A: Removes solvent, leaving dissolved solid behind.
Q: What is crystallisation?
A: Forms pure crystals from a solution as solvent evaporates.
Q: Key idea behind boiling point separation
A: Substances with lower boiling points evaporate first
What is simple distillation?
A liquid from a dissolved solid, OR
Liquids with very different boiling points (>50°C)
What is evaporation?
Removes solvent, leaving dissolved solid behind. (solubility)
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Week 2.1: The Atom31
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Week 2.0 Development of the models of the atom40
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Week 3.0 Electron shells and configurations28
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Elemental spectroscopy30
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Isotopes32
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Week 5: Periodic Trends25
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More periodic trends but this time it is actually periodic trends37
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Matter and properties32
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Separation Techniques36
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Mettalic bonding21
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Ionic Bonding26
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Naming chemical compunds31
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Common Chemical Reactions35
