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CH28 – More Lewis

Gilbert Lewis

Dates

  • P4 – Tuesday, October 31st
  • P5 – Tuesday, October 31st
  • P7 – Wednesday, October 31st

Review Lewis Structures

  • H / F bond only once
  • C / N / O / F always follow octet
  • C never lone pairs
  • Metals happy when partners happy

New Idea – Formal Charge

  • FC = start – assigned
  • assigned = lone electrons + half of bond electrons
  • goal – help decide which is better
  • example = carbon dioxide

New Idea – Ions

  • how do I represent ions?
  • example = nitrate ion

New Idea – Resonance

  • what to do when two structures equivalent
  • example = nitrate ion

New Idea – Exceptions to the Octet

  • more than 8 (sulfur hexafluoride)
  • less than 8 (aluminum hydride)

Practice, Practice, Practice

HCN IF3
H2CO SF4
NH3 AsF5
H2O XeF4
CF4 BrF5
PBr3 SF6
SO2 BaF2
BeCl2 XeF2
CH3Cl SO4-2
C2H2 NO3-1
HOCl  NaCl

For Each Substance (Two substances per side of page)

  • total number of valence electrons
  • Lewis dot structure
  • formal charges (each element)
  • central atom lone pairs / bonding pairs
  • central atom bonding domains / lone pairs

Information

This entry was posted on October 31, 2017 by in 1718 and tagged , , , .

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