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Organic Chemistry First Test
Chapter 1-3
52
Chemistry
Undergraduate 2
09/20/2007

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Term
What is Organic Chemistry?
Definition
-the study of compounds derived from living
organisms.
Term
What is the problem with "Vital Force"?
Definition
Synthesized urea had the exact same properties as urea from natural sources.
According to vitalism, these compounds would not be similar, but modern thought has concluded that both compounds are exactly the same.
Term
What is The Octet Rule?
Definition
atoms transfer or share electrons in such a way to attain a filled
shell of electrons.
Term
Ionic Bonds:
Definition
-The attraction of two oppositely charged particles.
-ionic compounds are composed of an anion (-’ve) and a cation
(+’ve) that are attracted to one another
Term
Covalent bonds:
Definition
bonds that are formed from the sharing of 2 electrons and the
overlap of orbitals.
Term
What is a hetero-atomic bond?
Definition
-An unequal sharing of the electrons can
occur to provide polar covalent bonds.
-Unequal electron distribution about a molecule results in a dipole moment.
Term
What is a Formal Charge?
Definition
The charge of an atom within a Lewis Structure (basically what is the
difference in number of e- for a free atom vs. the atom in a structure).

Formal charge= [group #] - [nonbonding atoms] - 1/2 [shared electrons]
Term
What type of molecules are usually Ionic?
Definition
Acids and Bases
Term
What is Resonance?
Definition
The actual structure.

-Only e- can be transfered.
Term
What is the 's' orbital defined as?
Definition
a standing wave (trident) that simply vibrates up (+) and
down (-).
Term
What is the 'p' orbital defined as?
Definition
a standing wave (trident) that is separated by a node and
the two halves vibrates up (+) and down (-) out of phase.
Term
Molecular Orbitals (overlapping)
Definition
Two atomic orbitals overlap to form two molecular orbitals:
1) Bonding molecular orbital (lower energy)
– Which we will discuss 99.9% of time
2) Nonbonding molecular orbital (higher energy)
Term
What is sigma bonding?
Definition
-Electron density is centered directly between nuclei
-These are single bonds or the first bond of a multiple bond
Term
What is pi bonding?
Definition
-Results from the overlap between two p oribtals
with electron density above and below bond axis
-These are the 2nd or 3rd bonds of a multiple bond
-‘Sideways overlap’
Term
What are the General Rules of Hybridization?
Definition
1. Both sigma bonding e- and lone pair e- can occupy hybrid orbitals.
– The number of hybrid orbitals is computed by adding the number of sigma
bonds to the number of lone pair e- on the atom.
2. Use the hybridization and geometry to provide the largest amount of space for
the e-.
– sp (2 areas of e- density; 180o; Linear)
– sp2 (3 areas of e- density; 120o ; Trigonal)
– sp3 (4 areas of e- density; 109.5o ; Tetrahedral)
3. If 2 or 3 pairs of e- form multiple bonds, the first of the bonds is a sigma bond,
formed by the overlap of a hybrid orbital; the 2nd and 3rd bonds are pi bonds
and come from the overlap of unhybridized p orbitals.
Term
What does Polarizability do?
Definition
It tends to increase with molecular weight and also
depends on molecular arrangements (isomers).
Term
What are Dipolar Forces?
Definition
attractive force that exists between the positive end of one polar molecule
and the negative end of the other.
Term
What is Hydrogen bonding?
Definition
attractive dipolar forces
between molecules in which hydrogen atoms are
covalently bonded to very electronegative elements
(O, N or F).
Term
How does one define a `general alkane`?
Definition
-ALL SINGLE BONDS
Term
What's the name of the alkane that only contains 1 carbon?
Definition
methane
Term
What's the name of the alkane that only contains 2 carbons?
Definition
Ethane
Term
What's the name of the alkane that only contains 3 carbons?
Definition
propane
Term
What's the name of the alkane that only contains 4 carbons?
Definition
butane
Term
What's the name of the alkane that only contains 5 carbons?
Definition
pentane
Term
What's the name of the alkane that only contains 6 carbons?
Definition
hexane
Term
What's the name of the alkane that only contains 7 carbons?
Definition
heptane
Term
What's the name of the alkane that only contains 8 carbons?
Definition
octane
Term
What's the name of the alkane that only contains 9 carbons?
Definition
nonane
Term
What's the name of the alkane that only contains 10 carbons?
Definition
decane
Term
First Rule of IUPAC
Definition
Determine the longest continuous chain of carbon atoms in molecule.
-This is the base name (i.e. hexane, pentane, butane, etc.)
-When two choices are available, choose the main chain with the highest
number of substituents.
Term
Second Rule of IUPAC
Definition
Number the carbon atoms in the longest chain, beginning with
the end of the chain nearest a substituent.
Term
Third Rule of IUPAC
Definition
Any substituent connected to the longest chain is named as the alkyl (-ane -> -yl) group and the location of this substituent is provided by the number of the carbon on the main chain it is
connected to.
• This is the name for the branch (i.e. hexyl, pentyl, butyl, etc.)
Term
Forth Rule of IUPAC
Definition
When two or more substituents are present, list them in alphabetical order. When two or more of the same alkyl substituents are present, use the prefixes di-, tri-, tetra-, etc. to avoid having the same alkyl group twice.
Term
What are the two conformations of Alkanes?

What are the three positions they can be in?
Definition
- Sawhorse Structure & Newman Structure

-Eclipsed, Straggered, or Skewed
Term
What is the most stable conformation for cyclohexane?
Definition
the `chair` form
Term
What is a`Resonance HYBRID`?
Definition
A single Lewis Structure that cannot completely describe a compound.
Term
What is the `Major Contributing Structure`?
Definition
The structure that is the lowest in Energy , filled octets, and least formal charge/
Term
What is an Arrhenius Acid/Base?
Definition
Acid- substance that provides H+

Base- substance that provides OH-
Term
What is a Bronstead-Lowry Acid/Base?
Definition
Acid- a species that can donate a proton (H+)

Base- a species that can accept a proton (H+)
Term
pH=?

[H+]=?
Definition
pH=-log[H+]

[H+]=10^-pH
Term
When discussing Acid Strength, the "___" the pKa, the "___" the acid.
Definition
When discussing Acid Strength, the "LOWER" the pKa, the "STRONGER" the acid.
Term
Ka=?
Definition
Ka=[H+][A-]/[HA]
Term
What are the three factors that are used to predict Acid Strength?
Definition
1) Electronegativity
2) Anion Size
3) Resonance
Term
Define Lewis Acids/Bases.
Definition
Acids- accepts e- pairs to form bonds.

Bases- donates e- pairs to form bonds.
Term
What is an `Electrophile`?
Definition
Lewis Acid- "lover of e-"
Term
What is a `Nucleophile`?
Definition
Lewis Base- "Lover of the Nucleus"
Term
What are Isomers?
Definition
different compounds that can be formed with the molecular formula.
Term
What is a Steroisomer?
Definition
isomers that differ only in the arrangement of atoms in space.
Term
Define Solubility.
Definition
"Likes Dissolve Likes"
Term
What are `Alkenes`?
Definition
-CONTAIN DOUBLE BONDS
Term
What are `Alkynes`?
Definition
-TRIPLE BONDS
Term
What are `Aromatics`?
Definition
hydrocarbons with very stable bonding.
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