CHEM 210 Midterm: Orgo Study Guide and Practice Problems
40 views80 pages

Orgo Study

Understand the relationship between the structure of a molecule and hybridization of
atoms within the molecule
Understand how to construct sigma and pi (and their antibonding counterpart) orbitals
from two atomic (or hybrid) orbitals
Understand whether two orbitals overlap and mix
Understand the significance of a node in an orbital (and its representation by shading
lobes)
Know how to name alkanes (don’t worry about the order of substituents, as we
discussed)
Know how to draw molecules in different conformations and how to represent them in a
Newman projection
see page 11
gauche
→staggered ,two groups Next to each Other →dihedral 600
anti →staggered ,two biggest groups directly apposite →dihedral 180 '
→lowest energy!
minimizes Steric strain
eclipsed →dihedral O.
→extreme steric strain
eclipsed →dihedral 120

Know how to construct and use an energy diagram for rotation about a bond.
Know values for a Me-Me gauche interaction (0.9 kcal/mol), a H-H eclipsed interaction
(1.0) and a H-Me eclipsed interaction (1.3).
Know how to convert between energy and equilibrium constant.
Know what we mean by primary, secondary, tertiary and quaternary carbons (or
hydrogens, attached to that carbon)
Understand (Bronsted) acid-base equilibria
Understand the meaning of pKa and its relationship to an equilibrium constant
Know how to determine an equilibrium constant for an acid base reaction if you are
given two pKa values
Know how to determine the fraction of an acid that is deprotonated in a solution of a
given pH
Me -Me gauche -og Me -me -5.3 geem
tf -Heclipsed =1.0
H.Me eclipsed =1.3
OG -
-
-Rtlnkeq -2.310g
Keg -OG
rt the
link
lnkeq . -0cg
RT
Req -.e
-OGIE
how many carbons are
Attached
proton donor (acid )
proton acceptor Cbase )JAAP
Tpka weak Add }describes acid
Kai "E¥
trpka strong acid udiisnsgoa.IM pka =-toga
decimals
@25IEaepkr.iylPka9TE.inmsP.km.e
:gI
keq40.IT?onwinproaed*stft
in the direction t
form the acid w/
larger pka
←given g) need to fend THAT . -
-
4) %dissociation
1) convert pkatoka Use equilibrium expression
ka.AE?f.7ILka--atIff#
"
ft¥ny .100
2) pH gives htt ]
soft 'T -
-CAT CHAT