21 Nov_Tue._Chemisty

21 Nov_Tue._Chemisty - The 3 rd row and heavier elements...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemisty  Ch. 8.11 21 Nov. (Tues.) Exceptions to the Octet Rule Boron trifluoride, BF 3 : -Boron in the BF 3  only has 6 electrons around it. -BF is electron deficient and acts as a Lewis acid (electron pair acceptor) Sulfur hexafluoride, SF 6: -Sulfur has 12 e- around it, exceeding the octet rule. -SF 6  is very sable! -SF 6  fills the 3s and 3p orbitals with 8 of the valence electrons, and place the other 4 in the  higher 3d orbitals. Comments About the Octet Rule p. 360 :F: :F: :F: n= 3 S l= 0.   1.   2. :F: :F :      S P   d The second row elements C, N, O, and F should always be assumed to obey the octet rule. The 2 nd These electon-deficient compounds are very reactive. The 2 nd accommodate only 8 electrons.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: The 3 rd row and heavier elements often satisfy the octet rule but can exceed the octet rule by using empty valence d orbitals. When writing the Lewis structure for a molecule, satisfy the duet or octet rule first. If electrons remain after the octet rule has been satisfied, then place them on the elements having available d orbitals. See sample exercise 8.7: PCl5-total # of valence e- = 5 + 5 x 7 = 40e P: 5e-Cl: 7e-:Cl: :Cl: P :Cl: : Cl: :Cl: 8.12 Resonance NO3-: a controversy between theory and experiment-Draw Lewis structure of NO3--Experiment: all N- O bonds are identical! NO3-: 5e- + 3 x 6e + 1e- = 24e-4 x 8e-: 32e-32e- - 24e- = 8e-8e-/ 2 =4 bonding pairs :O: :O: N :O:-Resonance Structures-Odd Electron Molecules-Formal Charges-Using Formal Charges to Evaluate Lewis Structures...
View Full Document

Page1 / 2

21 Nov_Tue._Chemisty - The 3 rd row and heavier elements...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online