Chapter 9
Recommended Problems: Brown-Box problems and suggested further problems in the back. Selection of
further problems in back of Chapter as good options. Brown box problems would be a very good start,
including the further suggeseted problems. VERY IMPORTANT: Lewis structures from Lab Exercises (note
that the full answers have been provided, along with geometries, via E-mail attachment sent on or about 7
April-Check FerrisConnect) Also, try 35, 39, 41, 47, 55, 59, 61, 65, 71, 75, 77, 83, 107, 120.
9.1 Ionic Bonds Neutral elements ionizing through redox to become ions following the octet
rule
Lewis dot structures for neutral and ionized elements, also proper e
configuration notation
Effect of charge and distance on Lattice energy “U”
Consider E = constant (Q1 x Q2/r) . Compare (qualitatively) stabilities of
ion pairs of crystals with differing charge and radius (r = distance between)
Energetics Born Haber Cycle (fig 9.3) . Going to gas phase atom from
elements in their standard form , cation/anion formation, coming together of
opposite ions to make crystal in 3-D. Q . Which step RELEASES the most
energy (is stabilizing/)
9.2 Electron config
of ions
a) Octet rule for Main Group Cations and Anions is most important of
these. Groups IA-IVA metals lose 1-4 e. Groups VA-VIIA elements
gain 3-1 e.
b) Tendency of transition metals to lose ns electrons first
c) In addition to octet rule predictor as expected (Tl+3,Pb+4, Sn+4, Bi+5
as ox states)
(Group # -2) charge is another pattern, as the two ‘s’ electrons only
are lost first for these. Result Tl+1,Pb+2, Sn+2, Bi+3
d) Transition metals ‘s’ electrons are often lost first.
9.3 Ionic Radii Ionic radii. Increasing (+) charge –effect on radius and why
Increasing (-) charge –effect on radius and why
Left-right and up down trends in radius (note that anions will behave
differently from cations and increasing charge (+ or -) has an effect as well
What is an isoelectronic series?
9.4 Covalent Bonds Potential Energy Diagram Fig 9.11 Know the important parts of this diagram.
Discussed extensively in class. What allows covalent bonds to be stable?
Coordinate covalent bonds. How different from ‘regular” covalent bonds?
Octet Rule see also above (previous sections) and how to make multiple
bonds.
