General Chemistry: Properties of Matter, Naming Compounds, and Formulas

Chemistry Definitions

  • Chemistry: Study of matter, its properties, composition, and structure.
  • Matter: Anything occupying space and having mass.
  • Volume: Space occupied by a three-dimensional object.
  • Mass: Constant measure of the amount of matter.
  • Weight: Force exerted on a body by gravity (9.8m/s29.8 m/s^2).
  • Atom: Smallest building block of matter.
  • Proton: Positively charged particle in the nucleus (Ernest Rutherford).
  • Neutron: Uncharged particle in the nucleus (James Chadwick, 1932).
  • Electron: Negatively charged particle surrounding the nucleus (J.J. Thomson, 1897).
  • Ion: Electrically charged atom (positive or negative).
  • Cation: Positively charged ion (+).
  • Anion: Negatively charged ion (-).

Historical Perspective

  • Ancient Greeks: Believed in four elements (earth, air, fire, water).
  • Democritus: Coined "atoms" as indivisible building blocks, uniform, solid, hard, incompressible, and indestructible.

States of Matter

  • Solid: Compacted particles, definite shape/volume, incompressible, slow diffusion, high density.
  • Liquid: Slightly far particles, distinct volume, shape varies, medium density, slower diffusion than gas.
  • Gas: Far particles, fills container, compressible, rapid diffusion, low density.
  • Density =mass/volume= mass / volume

Mixture

  • Combination of two or more substances.

Homogeneous

  • Uniform composition (e.g., coffee, air).
  • Pure substance: Fixed content and properties.
    • Element: One type of atom.
    • Compound: More than one type of atom.
  • Solution: Solute(s) dissolved in a solvent.
  • Radioactive element: Spontaneous emission of energetic particles.

Heterogeneous

  • Visibly distinguishable components.
  • Colloid: Small particles, requires methods like centrifugation for separation.

Physical vs. Chemical Change

  • Physical Change: Alters form without changing composition (e.g., state change).
  • Chemical Change: Transforms substance into new products (e.g., combustion).

Properties of Matter

  • Matter exists as solid, liquid, or gas.

Physical Properties

  • Observed without changing chemical composition.
Intensive
  • Independent of amount (e.g., temperature, density, color).
  • Ductility: Ability to be stretched into wire.
  • Malleability: Ability to be hammered into sheets.
  • Diffusion: Ability to scatter or spread out.
  • Solubility: Ability to dissolve in a solvent.
Extensive
  • Dependent on amount (e.g., size, mass, volume).

Chemical Properties

  • Observed when matter reacts with another substance (e.g., flammability, oxidation).

Additional Properties

  • Brittle: Breaks easily under force.
  • Strength: Resistance to deformation.
  • Hardness: Resistance to penetration.
  • Toughness: Resistance to fracture under impact.
  • Brittleness: Breaks easily under shock.
  • Ductility: Deformation before breaking.
  • Elasticity: Regains original shape after load removal.
  • Plasticity: Undergoes permanent deformation.

Atomic Structure Reminders

  • Nucleus: Positively charged center with protons and neutrons.
  • Orbits: Contain electrons, overall atom is neutral.
  • Exothermic: Heat is released.
  • Endothermic: Heat is absorbed.
  • Rust formation: Oxidation reaction (iron + oxygen + moisture).
  • Ferrous oxide: FE2+O2−FE^{2+}O^{2-}
  • Ferric oxide: Fe3+O2−Fe^{3+}O^{2-}

Miscibility

  • Miscible: Liquids mix (e.g., vinegar + toyo).
  • Immiscible: Liquids don't mix (e.g., oil + water).

Separation Techniques

  • Decantation: Separating liquid from solid after settling.
  • Chromatography: Separating substances based on absorption on a surface.
  • Centrifugation: Using centrifugal force to settle precipitates.
  • Distillation: Evaporation and condensation of liquid (separate mixture with different boiling points).
  • Evaporation: Separating dissolved solid from liquid by heating.
  • Filtration: Separating insoluble solid from liquid using filter paper.
  • Mechanical separation: Using tools to separate components.
  • Magnetic separation: Separating magnetic solid from mixture.

The Periodic Table

  • Elements arranged by increasing atomic number.
    • Periods: Horizontal rows related to electron orbitals.
    • Groups/Families: Vertical columns with similar valence electrons/chemical properties.
  • Orbitals: s (spherical), p (principal), d (diffuse), f (fundamental).

Elements with Latin Names

  • Sodium (Na - Natrium)
  • Potassium (K - Kalium)
  • Iron (Fe - Ferrum)
  • Copper (Cu - Cuprum)
  • Silver (Ag - Argentum)
  • Tin (Sn - Stannum)
  • Antimony (Sb - Stibium)
  • Tungsten (W - Wolfram)
  • Gold (Au - Aurum)
  • Mercury (Hg - Hydrargyrum)
  • Lead (Pb - Plumbum)

Average Atomic Mass and Isotopes

  • Isotopes: Same protons, different neutrons

Calculations

  • Protons = Atomic Number
  • Electrons = Atomic Number
  • Neutrons = Atomic Mass - Atomic Number
  • Average Atomic Mass =∑(atomic mass)(percent of abundance)= \sum (atomic \space mass)(percent \space of \space abundance)

Naming Compounds

  • Ionic: Metal + Nonmetal (or polyatomic ion)
  • Covalent: Two Nonmetals

Octet Rule

  • Atoms 'want' 8 valence electrons, achieve by gaining/losing electrons.

Naming Ions

  • Cations (positive) - Name of element + "ion"
  • Anions (negative) - Root + "ide" + "ion"

Transition Metals

  • Stock Naming (oxidation state in Roman Numerals)
  • Classical Naming ("-ous" for lower, "-ic" for higher oxidation states)

Polyatomic Ions

  • "-ate": Larger number of oxygen atoms
  • "-ite": Smaller number of oxygen atoms

Naming Binary Compounds

  • Cation name + Anion Root + "ide"

Naming Covalent Compounds

  • Prefixes indicate number of atoms (mono, di, tri, etc.)

Naming Acids

Binary Acids

  • "Hydro-" + Anion Root + "-ic" + "acid"

Ternary Acids (Oxoacids)

  • "-ate" becomes "-ic"
  • "-ite" becomes "-ous"

Bases

  • Metal + Hydroxide (OH-)

Formula Mass & Molar Mass

  • Molar Mass: 6.022×10236.022 \times 10^{23}
  • Formula Mass of Polyatomic Ions: sum of the average atomic masses (expressed in atomic mass units).
  • Percent Composition: mass of elementformula mass×100\frac{mass \space of \space element}{formula \space mass} \times 100

Empirical and Molecular Formulas

  • Empirical Formula: Simplest whole number ratio of elements.
  • Molecular Formula: Actual number of atoms of each element in a molecule.