Chem unit 5

  1. covalent bonds:
    The covalent bonds that results from sharing valence electrons.
  2. Molecule
    Is formed when two or more atoms bond covalently.
  3. Single covalent bonds:
    • When only an atom shares only one pair of electrons.
    • 2 single covalent bonds: H2O
    • 3 single covalent bonds: NH3
    • 4 single covalent bonds: CH4
  4. Double covalent bonds
    when 2 pairs f electrons are shared between two atoms.
  5. Triple covalent bonds:
    when three pairs of electrons are shared between two atoms. (N2)
  6. Bond length:
    • it is the distance from the center of one nucleus to the center of another nucleus of two bonded atoms. The closer the stronger the bond.
    • A single bond is weaker than a double bond. And a double bond is weaker than a triple bond.
  7. Bond dissociation Energy
    • The amount of energy required to break a specific covalent bond
    • The smaller the bond length, the greater the bond dissociation energy.
  8. Naming binary molecular compounds
    • 1-mono
    • 2-di
    • 3-tri
    • 4-tetra
    • 5-penta
    • 6-hexa
    • 7-hepta
    • 8-octa
    • 9-nona
    • 10-deca
  9. Resonance:
    • It is a condition that occurs when more than one Lewis structure can be written for a molecule or ion.
    • nitrite can be written in several ways.
  10. Exceptions to the Octet Rule:
    • NO2
    • Cl2
    • NO
    • BH3
    • PCl5
  11. molecular shapes
    • linear
    • trigonal planar
    • tetrahedral
    • Trigonal pyramid
    • bent
    • Trigonal bipyramidal
    • Octahedral
  12. Polar bonds:
    unequal sharing.
  13. Nonpolar bonds
    Electrons are equally shared between the atoms
  14. EN difference and bond character
    • >1.7: mostly ionic
    • 0.4-1.7: polar covalent
    • <0.4: mostly covalent
    • 0: nonpolar covalent
Card Set
Chem unit 5
Covalent Bonding