Mixtures

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Mixtures
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Mixtures ? Substances separated by physical
methods Compounds ? Substances separated by
chemical methods
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Mixtures

• Combo of 2 or more pure substances
• Physically combined NOT chemically combined
• Each substance retains its own identity and
  properties

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Mixtures

• Variable composition
• No unique properties
• Ex sugar and sand mixed together
• Separated by physical methods
• May be homogeneous or heterogeneous

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Types of Mixtures

• Heterogeneous See boundary or regions that look
  different
• Ex
• colloids
• suspensions
• ice water
• granite
• cereals

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Heterogeneous mixtures cereal/granite
Colloid milk
Suspension smoke/smog
Heterogeneous mixture ice water
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• Homogeneous constant composition throughout,
  single phase
• Ex
• Solutions (all 3 phases)
• Air
• Windex
• kool-aid

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Homogeneous Solutions
Drink mix
Window cleaner
Air
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Hints for Mixtures

• Solutions (gas liquid phases) transmit light
• No particles big enough to scatter light
• Look translucent (see-through)
• Suspensions look cloudy scatter light
• Particles big enough to scatter light
• Settle upon standing

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Where does this liquid fit? Homogeneous? Heteroge
neous?
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Particle Diagrams
Atoms only monatomic element
?
?
Molecules diatomic element
?
?
?
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Particle Diagrams

• Molecules
• triatomic compound

?
?
?

• Mixture
• monatomic element
• diatomic element
• triatomic compound

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Conservation of Mass

• Mass before Mass after
• atoms before atoms after

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Separating Mixtures

• Physically combined
• Separation based on physical properties
• Sorting Appearance
• Filtration Size
• Distillation Boiling Point
• Crystallization Solubility
• Magnet Magnetization
• Chromatography Travel ability

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Filter Solid particles can be separated from
liquid
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Distillation
Used to separate liquids with different boiling
points
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Paper Chromatograhy
Can separate liquids with different solubilities
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Crystallization
Can separate solids dissolved in liquids