Admin stuff

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Admin stuff

• OWLs next set due Friday
• Reading Today 3.3-3.4
• 9.8
• No SI session Tuesday
• Test 2 discussed at end of class

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Naming compounds
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Halloween atoms
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Polyatomic (molecular) ions
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Consider these oxoanions with the maximum number
of oxygens for that element
Total oxidation state of Central atom
Oxygens Ion charge

• NO3
• CO3 2
• SO4 2
• PO43
• ClO4
• CrO42

What charge do we expect for a MnO4 ion?
Use a numeric response
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Names of some ionic compounds

• CaCl2
• KHCO3
• Ba(OH)2
• TiO
• Co2O3

Neighbor quiz

• calcium chloride
• potassium hydrogen carbonate
• barium hydroxide
• titanium(II) oxide
• cobalt(III) oxide

• copper(II) cyanide
• barium hypochloride
• ammonium nitrite
• lithium carbonate
• sodium dihydrogen phosphate

Cu(CN)2 Ba(ClO)2 NH4NO2 Li2CO3 KH2PO4
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Chemical bonding
Covalent
Ionic
AB-
AB
(shared electrons)
(transferred electrons)
Different naming rules for each
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Electronegativity

• Electronegativity (c) is the tendency of an atom
  to pull electrons towards it
• The atom with the larger (c) has a larger share
  of the electrons, and Dc determines the bond
  polarity

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Bonding

• Three classes of bonds
• ionic (complete electron transfer)
• polar covalent (partial electron transfer)
• nonpolar covalent (equal sharing)

• Judge the type of bond from electronegativities
• Large Dc (above 1.5 or 2.0) results in ionic
  compounds

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Examples

• (1) CH (2) SO (3) ClNa

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Chemical bonding
Covalent
Ionic
AB-
AB
(shared electrons)
(transferred electrons)
Different naming rules for each
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Test 2 results

• Mean 75 High 99
• Number on back of test is points lost out of 100
• Withdraw?
• Reasons to Help avoid academic probation
• Reasons NOT to May lose full time status
• Miss out on chance to practice material
• Lose chance for a lab waiver

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