Unit 1 - Particles & Purification

1.1 Solids, Liquids & Gases

  • Three states of matter

    • Water can exist as all

    • Solid - definite shape and volume

      • fixed pattern, only vibrate, close together

    • Water - definite volume, takes shape of container

      • no fixed pattern, slides past, close together

    • Gas - no definite volume or shape

      • random, everywhere rapidly, far apart

  • Changes of state

    • Melting

      • solid to liquid

    • Freezing

      • liquid to solid

    • Boiling

      • liquid to gas

    • Condensing

      • gas to liquid

    • Sublimation

      • solid to gas

      • gas to solid


  • Three types of particles

    • atom - smallest particle, cannot be broken down

    • molecule - two or more atoms together

    • ion - group of atoms has an electrical charge

  • Kinetic Particle Theory

    • temperature increases kinetic energy of particle increases

    • pressure of gases also increase

  • Brownian Motion

    • Random Motion of dust particles

    • Collision of dust particles with other air molecules

  • Diffusion

    • Random movement of particles from high to low concentration

    • temperature increase, kinetic energy increase, rate of diffusion increase

  • Heating and Cooling Curve

    • time temperature graph when heated or cooled

  • Paper chromatography

    • Baseline at 3cm with pencil

    • drop of mixture placed on baseline

    • filter paper in a solvent like water or ethanol

    • number of spots depends on number of components

    • soluble components travel faster.

1.2 Purification

  • Pure substances

    • Fixed melting and boiling point (impurities change melting and boiling point)

    • Made of only one type of atom

    • Compounds have a fixed ratio

    • Elements and compounds are pure substances, mixtures are not

  • Simple Distillation

    • separation between two liquids with different boiling points

    • two mixed liquids are heated

    • liquid with lower boiling point comes out first

    • then condense and get liquid

  • Fractional Distillation

    • separation between two or more liquids with different boiling points

  • Filtration

    • separation between insoluble matter from a liquid

    • through filter paper

End of Chapter