Mixtures Matter Substances Elements Compounds Mixtures Heterogeneous Mixtures
Mixtures
Matter Substances Elements Compounds Mixtures Heterogeneous Mixtures Homogeneous Mixtures Substances separated by physical methods Compounds Substances separated by chemical methods
Mixtures • Combo of 2 or more pure substances • Physically combined NOT chemically combined • Each substance retains its own identity and properties
Mixtures • Variable composition • No unique properties • Ex: sugar and sand mixed together • Separated by physical methods • May be homogeneous or heterogeneous
Types of Mixtures • Heterogeneous: See boundary or regions that look different Ex: • colloids • suspensions • ice water • granite • cereals
Heterogeneous mixtures: cereal/granite Colloid: milk Suspension: smoke/smog Heterogeneous mixture: ice water
• Homogeneous: constant composition throughout, single phase Ex: • Solutions (all 3 phases) • Air • Windex • kool-aid
Homogeneous Solutions: Drink mix Air Window cleaner
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
Where does this liquid fit? Homogeneous? Heterogeneous?
Particle Diagrams Atoms only: monatomic element Molecules: diatomic element
Particle Diagrams Molecules: • triatomic compound Mixture: • monatomic element • diatomic element • triatomic compound
Conservation of Mass • Mass before = Mass after • # atoms before = # atoms after
Separating Mixtures • Physically combined • Separation based on physical properties – Sorting: Appearance – Filtration: Size – Distillation: Boiling Point – Crystallization: Solubility – Magnet: Magnetization – Chromatography: “Travel” ability
Filter: Solid particles can be separated from liquid
Distillation Used to separate liquids with different boiling points
Paper Chromatograhy Can separate liquids with different solubilities
Crystallization Can separate solids dissolved in liquids
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