Year 11 Chemistry Notes

Properties of Matter

1.1 Properties of Matter (Knowledge and Understanding)

  • Inquiry question: How do the properties of substances help classify and separate them?
  • Key Activities:
    • Explore homogeneous and heterogeneous mixtures through practical investigations:
    • Using separation techniques based on physical properties (ACSCH026).
    • Calculating percentage composition by weight of components (ACSCH007).
    • Investigate inorganic substances nomenclature using IUPAC naming conventions.
    • Classify elements based on properties and position in the periodic table using:
    • Physical properties
    • Chemical properties

Definition of Matter

  • Matter: Anything that takes up space and has mass.
    • Composed of atoms, which are miniscule particles.
    • Must display properties of mass (measured in kg or g) and volume (measured in m³, cm³, L, mL).

States of Matter - Particle Theory

  • Particle Theory: Explains properties of solids, liquids, and gases:
    1. Solids:
    • Particles vibrate around fixed positions.
    • Have definite volume and shape; incompressible.
    1. Liquids:
    • Particles can slip past each other.
    • Variable shape; definite volume; very slightly compressible.
    1. Gases:
    • Particles in rapid constant motion.
    • No definite shape or volume; highly compressible.

Comparison of States of Matter

PropertySolidLiquidGas
ShapeDefiniteVariableVariable
VolumeDefiniteDefiniteVariable
CompressibilityIncompressibleVery slightlyHighly
DiffusionNegligibleSlowFast
Thermal ExpansionSlightlyModeratelyHighly

Classifications of Matter

  • Elements:

    • Consist of one kind of atom; cannot be broken down.
    • Exist as atoms (argon) or molecules (nitrogen).

  • Compounds:

    • Consist of two or more different elements.
    • Can be broken down into simpler types by chemical means.
    • Have properties different from component elements, consist of fixed ratios.

  • Mixtures:

    • Consist of two or more different elements/compounds physically intermingled.
    • Can be separated by physical means; often retain properties of components.

Separation Techniques for Mixtures

  • Methods:
    • Filtration: Separation of undissolved solids from liquids/gases.
    • Evaporation: Removing a component by vaporization.
    • Crystallisation: Formation of crystals from solutions based on solubility differences.
    • Decantation: Pouring off a liquid from settled solids.
    • Centrifugation: Spinning to separate components by density.
    • Distillation: Separation based on boiling point differences.
    • Chromatography: Distinguishing components in a mixture based on movement through a medium.

Practical Investigations

  • Separation of solids:

    • Sieving, sedimentation (gravity based separation), magnetic separation, froth flotation.

  • Separation of dissolved solids from liquids:

    • Evaporation and crystallisation.

  • Separation of miscible liquids:

    • Distillation for components with differing boiling points; fractional distillation for close boiling points.

  • Separation of gases:

    • Liquefaction and fractional distillation for atmospheric gases.

IUPAC Nomenclature Guidelines

Covalent Compounds:

  • Write the formula, name the elements, apply prefixes for quantity.

Ionic Compounds:

  • Write stocks and adjust numbers for neutrality in charge.

Periodic Table Classification

  • Metals:
    • Generally, solid, shiny, malleable, ductile, good conductors of heat/electricity.
  • Non-metals:
    • Brittle, poor conductors, can be gases or solids.
  • Metalloids:
    • Intermediate properties useful in semiconductor applications.