Notesale: Turn your study into money

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 Molecules- Are two or more atoms which are chemically bounded
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 Compounds- When two or more different elements join together/combine
chemically they form a compound
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 Mechanical separation methods- A method which can successfully separate
something without the use of chemicals
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 Physical change- A change in shape, size or state that does not change the chemical
composition of the substance
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This change can be reversed
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 Chemical change- A change in the chemical composition of a substance, which
results in a new substance being formed
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 Chemical properties- Properties of a substance that give it the ability to undergo
change in chemical composition
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For example, Air is a gas which
consists of Nitrogen, Oxygen, Hydrogen and Carbon Dioxide
 Gas particles are vastly separated (This is the reason for why most gases are
odourless and colourless)
 Gases have no fixed shape
 Gases have no fixed volume
 Gases are easily compressible
 Gas particles have high amounts of kinetic energy

SEPERATION TECHNIQUES

ARE TECHNIQUES WHICH SEPARATE SUBSTANCES FROM EACH
OTHER BASED ON THEIR DIFFERENT PHYSICAL PROPERTIES
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Separates substances by whether they are attracted to a magnet
2
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The other substances in the mixture must be non-magnetic
 Chromatography:
1
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Usually used to separate coloured substances like ink
 Distillation:
1
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Can also be used to separate liquids from solids
3
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Separates substances by their solubility and their size
2
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The other substance must be a liquid
 Evaporation:
1
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The one downside of evaporation is that the solvent is “lost” as a gas and only
the solute (solid) remains
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This process is
called dissolving
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Only when
the right solid meets the right liquid, does this process occur
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FACTORS WHICH AFFECT THE RATE OF DISSOLUTION
 Temperature:
# Higher temperature means more kinetic energy, this means more
successful collisions between the solvent particles and the solute particles, which
results in a faster break down of the solute
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 Mixing:
# Stirring or mixing incorporates the solvent with the solute manually
rather than waiting for it to occur due to random motion (Liquid particles moving
around randomly and colliding with the solid particles)
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 Surface area:
# If an solute is spread out this means it will cover more surface area
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Hence faster dissolution
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 Obviously because gases have high levels of kinetic energy they will diffuse at
faster rates
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EXAMPLE: A heater heats the room by blowing hot air into the room
 Brownian motion- The random movement of particles of a substance in a fluid
(liquid or gas)
 Neutralization reaction- A type of chemical reaction in which a strong base and a
strong acid react with each other to form water and salt
 𝐵𝑎𝑠𝑒 + 𝐴𝑐𝑖𝑑 → 𝑁𝑒𝑢𝑡𝑟𝑎𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛 𝑟𝑒𝑎𝑐𝑡𝑖𝑜𝑛 = 𝐹𝑜𝑟𝑚𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑆𝑎𝑙𝑡 𝑎𝑛𝑑 𝑊𝑎𝑡𝑒𝑟
 𝑆𝑎𝑙𝑡 + 𝐴𝑙𝑘𝑎𝑙𝑖 → 𝑆𝑎𝑙𝑡 + 𝐼𝑛𝑠𝑜𝑢𝑙𝑎𝑏𝑙𝑒 𝑚𝑒𝑡𝑎𝑙𝑙𝑖𝑐 𝑏𝑎𝑠𝑒
 𝑀𝑒𝑡𝑎𝑙 + 𝐴𝑐𝑖𝑑 → 𝑆𝑎𝑙𝑡 + 𝐻𝑦𝑑𝑟𝑜𝑔𝑒𝑛
 𝑀𝑒𝑡𝑎𝑙 + 𝑂𝑥𝑦𝑔𝑒𝑛 → 𝑀𝑒𝑡𝑎𝑙 𝑂𝑥𝑖𝑑𝑒
 𝑀𝑒𝑡𝑎𝑙 + 𝑊𝑎𝑡𝑒𝑟 → 𝑀𝑒𝑡𝑎𝑙 𝐻𝑦𝑑𝑟𝑜𝑥𝑖𝑑𝑒 + 𝐻𝑦𝑑𝑟𝑜𝑔𝑒𝑛
 𝐴𝑐𝑖𝑑 + 𝑀𝑒𝑡𝑎𝑙 𝑂𝑥𝑖𝑑𝑒 → 𝑆𝑎𝑙𝑡 + 𝑊𝑎𝑡𝑒𝑟
 𝐴𝑐𝑖𝑑 + 𝐶𝑎𝑟𝑏𝑜𝑛𝑎𝑡𝑒 → 𝑆𝑎𝑙𝑡 + 𝐶𝑎𝑟𝑏𝑜𝑛 𝐷𝑖𝑥𝑜𝑖𝑑𝑒 + 𝑊𝑎𝑡𝑒𝑟
 Alkali- A base which is soluble(dissolves) in water
 Solubility- Ability to dissolve in an liquid
 Solute- A substance dissolved in another substance
 Solvent- A substance that dissolves a solute, e
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water



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