Chemistry Midterm Review

  1. Differentiate between Matter and Energy:
    Matter: Particulate (chunk-like) and moves in definite paths.

    Energy: Continuous (wave-like) and moves in all directions.
  2. Orbital Energy Depends On:
    • 1. Greater nuclear charge, lower (stabalize) orbital energy.
    • 2. Electron-electron repulsions, raise (destabalize) orbital energy.
    • 3. Electrons in outer orbitals (higher n) are shielded from the full nuclear charge, so they have higher energy.
    • 4. Orbitals with good penetration (having electron density close to nucleus), have lower energy.
  3. Effective Nuclear Charge (Z_Eff)
    The nuclear charge an electron actually experiences as a result of shielding effects due to the presence of other electrons.

    Shielding = lower Z_eff = charge makes electron easier to remove.
  4. Down a group:
    • Zeff Constant
    • Radius Increases
    • EA Less Negative
    • EN Decreases
    • IE Decreases
  5. Across a Group (Left To Right)
    • Zeff Increases
    • Radius Decreases
    • IE Increases
    • EA More Negative
    • EN Increases
  6. Reducing Agent
    • Loses electron
    • Is oxidized
    • Oxidation # Increases
  7. Oxidizing Agent
    • Gains electron
    • reduced
    • Oxidation # Decreases

    *Halogens are easily reduced.
  8. How can you tell if a substance is a good oxidizing agent or a good reducing agent?
    • RA:
    • -easily loses electron (low IE)
    • -Is in unusually low oxidation states

    • OA:
    • -easily gains electron (highly -ve EA)
    • -is in unusually high oxidation states
  9. Hydrogen
    • -Colourless gas, low mp, low bp
    • -Most abundant element in universe (Stars)
    • -Normally a nonmental
    • -Preperation:
    • 1.Most abundant source on earth is H20
    • 2.Extraction of the element by reduction of H2O. Electrolysis is NOT a practical method.
    • -Uses: 1. Production of Ammonia
    • 2. In petroleum refining, converting oils to fats.
    • Disadvantages: no cheap source and transport and storage are challenging.
Card Set
Chemistry Midterm Review
Key Point