Chem 2323
Organic Chemistry I
Spring 2013
Review Sheet for Exam #1
If something is underlined, there will be a test question on that material guaranteed. The topics that I put on the
quizzes are noted by: (quiz #X) after the concepts.
1) Atomic structure and bonding
a. Know s,p,d orbitals and how to draw electron configurations (quiz #1).
i. Be prepared for configurations of cations and anions too.
b. Know how hybrid orbitals form (sp, sp2, sp3) and how this leads to structure predictions and
knowing bond angles (quiz #1).
c. Know difference between sigma (σ) and pi bonds (π).
i. Be prepared for hybrid orbitals that contain lone pairs of electrons.
d. Know how to draw skeletal structures (don’t show C’s, don’t show H’s that are connected to C’s,
show all other atoms) (quiz #1).
2) Polar covalent bonds (acids/bases)
a. Know difference between ionic, polar covalent, and non-polar covalent bonds.
b. Be able to identify polar bonds within a molecule.
c. Be able to identify overall dipole moments of molecules (the overall polarity).
i. Important to know 3D shapes of molecules for symmetry .
d. Know how to calculate formal charges .
i. Do “mathy” formula (formal charge = # valence electrons in free atom - # valence in
bonded atom).
e. Know what resonance is and how to draw resonance structures (quiz #2).
i. Recognize “three atom groupings” to help draw them.
ii. Real structure is a hybrid of all resonance structures.
f. Know how to use pKa to tell if a reaction will occur as it is written. Will the acid give up its
proton? (quiz #2)
i. Lower pKa = stronger acid (more likely to give up H+)
g. Know how the resulting resonance structures formed after an acid gives up a H+ help dictate
how acidic a molecule is (quiz #2).
h. Know the intermolecular forces (dipole-dipole, London dispersion, hydrogen bonding) and
which forces will apply to which molecules.
3) Alkanes
a. Know about functional groups.
b. Recognize straight chain alkanes (Cn2n+2) and know methane, ethane, propane, butane,
pentane, hexane, heptane, octane, nonane, and decane (number of C’s = 1-10).
c. Know about isomers.
i. constitutional = different connections between atoms
ii. Stereoisomers = same connections between atoms but different 3D arrangement (like
cis or trans conformers in cycloalkanes)
d. Know about alkyl groups: methane becomes methyl, propane becomes propyl, etc.
i. Know isopropyl, sec-butyl, tert-butyl, isobutyl.
e. Know about primary (1°), secondary (2°), tertiary (3°), quaternary (4°) carbons.
f. Know how to name alkanes
i. Follow the rules and you’ll be OK
g. Know the properties of alkanes.
i. Non-reactive, as # of carbons increases so do melting point and boiling point, straight
chain alkanes have higher bp and mp than do branched alkanes.
h. Be able to draw the Newman projections for ethane.
i. Be able to draw the Newman projections for other alkanes.
i. Hardest part may be recognizing which bond you are looking down (practice!).
j. Know how to use the “energy cost table” (containing torsional strain energy costs and steric
strain energy costs) to calculate the potential energy map of alkanes as a bond is rotated.
4) Cycloalkanes
a. Be able to name them, the simple ones with one ring and some substituents.
b. Be able to recognize cis and trans isomers (not always easy in the chair conformations).
c. Know how the three main contributors of ring strain (angle strain, torsional strain, steric strain)
contribute to different cycloalkanes (cyclopropane, cyclobutane, cyclopentane, cyclohexane).
d. BE ABLE TO DRAW THE CHAIR CONFORMATION OF CYCLOHEXANE!
i. Also be able to draw axial and equatorial bonds and do ring flips.
e. Be able to draw mono and di-substituted cyclohexanes and use the “steric strain table” to
calculate how much strain there is.
f. Know the basics about polycyclic molecules (cis vs trans).