Transcript Organic Chemistry

Organic Chemistry:
Study of carbon based molecules
Bonding
Covalent (share valence e-)
All Nonmetals
Made of carbon, hydrogen and other
nonmetals like sulfur, oxygen, nitrogen etc.
Carbon Based Molecules
Carbon Atoms Form the “Backbone”
Carbon has 4 valence and needs 4 more
ALWAYS forms 4 bonds
Bonds can be single, double or triple
Due to variety and number
of bonds carbon can form
you can have an enormous
number of combinations
Properties of Organic
Compounds
Melting Point Temp.
Relatively Low MP (compared to ionic, metallic)
MP depends on strength of IMF
Non-polar molecules: (Lowest MP)
Have VDW attractions (weak)
Larger NP molecules have higher MP than smaller
Polar molecules: (Slightly Higher MP)
Dipole-dipole attractions or H-bonding
Molecules held together more
Solubility
Polar molecules:
soluble in polar solvents like water
Nonpolar molecules:
soluble in nonpolar solvents like hexane
Look for:
Symmetry = nonpolar
Assymmetry = polar
Conductivity in Solution
Organic Molecules usually DO NOT ionize
don’t conduct in solution
NONELECTROLYTES
Important Exception:
ORGANIC ACIDS
Ex: CH3COOH
Also…
Organic Molecules:
Undergo combustion in the presence of
oxygen
Slow rates of reaction due to complexity of
bonds (often catalyst needed)
Breakdown/decompose at low temperature
compared to other compounds
Formula Writing and
Drawing Molecules
Types of Formulas
Molecular
 Empirical
 Structural
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Condensed Structural
Organic Prefixes (Table P)
Meth
Eth
Prop
But
Pent
Hex
Hept
Oct
Non
Dec
Indicate how many carbon atoms are in the entire molecule
You will only see molecules with a max of 10 carbons
Homologous Series of
Hydrocarbons (Table Q)
Have unique general “formula”
 Each member of the series differs by one
carbon and a certain # of hydrogen
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Alkanes
General Formula: CnH2n+2
All single bonds between carbon atoms
Name ends in “ane”
SATURATED hydrocarbons
(holding as many hydrogen atoms as possible)
http://www.kentchemistry.com/links/organic/orgonaming1.htm
Alkenes
General Formula: CnH2n
One double carbon to carbon bond
*Address needed for bond location
Name ends in “ene”
UNSATURATED hydrocarbons
(not totally filled with hydrogen)
http://www.kentchemistry.com/links/organic/orgonaming2.htm
Alkynes
General Formula: CnH2n-2
One triple carbon to carbon bond
*Address needed for bond location
Name ends in “yne”
UNSATURATED hydrocarbons
(not totally filled with hydrogen)
http://www.kentchemistry.com/links/organic/orgonaming3.htm
dienes, diynes etc…
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Have multiple double or triple bonds.
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Give the address for each multiple bond.
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End of name becomes “-diene…or –triene”

Use prefix “di/tri/tetra/penta” etc…if more
than one of the same thing on the chain.
http://www.kentchemistry.com/links/organic/orgonaming5.htm
http://www.kentchemistry.com/links/organic/orgonaming6.htm
Branching Hydrocarbons

Have hydrocarbon “branches” off the main
carbon chain.

Called “alkyl” groups
Naming Branched Hydrocarbons

Find longest continuous carbon chain and
name it (parent chain)

Find address of each branch

Count carbons in each branch
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Name branches using prefix ending in “yl”
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Ex: 2 carbon branch would be an “ethyl” branch.
Note:
If more than one of the same type of branch use
“di”, “tri”, “tetra” etc…instead of repeating the name
Isomers

Same molecular formulas, but different
structural formulas.

Atoms in the molecule have a different
arrangement.
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The more atoms the larger the number of
possible isomers
http://www.kentchemistry.com/links/organic/isomersofalkanes.htm
Cyclical Hydrocarbons
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Form rings
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Start with “cyclo-”
http://www.kentchemistry.com/links/organic/orgonaming7.htm
Benzene Series
Benzene Series:
6 carbon ring with alternating double bonds.
Electrons in double bonds “resonate” between
bond sites giving more strength to all the bonds
Branches and functional groups are often
attached to the ring
Ortho/Meta/Para locations
http://www.kentchemistry.com/links/organic/orgonaming4.htm
Organic Functional Groups
Reference Table R
Halides
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Contain one or more halogen atoms.
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Fluoro / chloro / bromo / iodo prefix
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Use address
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Use di, tri, tetra if more than one of same
http://www.kentchemistry.com/links/organic/halides.htm
Alcohols
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Have one or more “Hydroxyl” groups (-OH)
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Use address
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Name ends in “-ol”
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If more than one (–OH), name ends in “diol”, or “triol”
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Important Example: Glycerol or 1, 2, 3 propantriol
Types of Alcohols

Primary
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Secondary
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Tertiary
http://www.kentchemistry.com/links/organic/alcohols.htm
Aldehydes
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Carbon double bonded to oxygen at end
of a carbon chain (“carbonyl” group)
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ADDRESS NOT NEEDED (always at end!)
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End in “–al”
http://www.kentchemistry.com/links/organic/Aldehydes.htm
Ketones
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Carbon double bonded to oxygen in middle
of a carbon chain (“carbonyl” group)
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Use address

End in “-one”
http://www.kentchemistry.com/links/organic/Ketones.htm
Ethers
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Oxygen atom within carbon chain
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Count carbon atoms on either side of oxygen
and name them like “alkyl” branches.
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“Butterflies” with belly buttons
http://www.kentchemistry.com/links/organic/ethers.htm
Organic Acids

At the end of the carbon chain is a “carboxyl”
group containing two oxygen atoms.
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ADDRESS NOT NEEDED (always at end!)
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End in “-oic acid”
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Has an acidic hydrogen that ionizes so these are
ELECTROLYTES
http://www.kentchemistry.com/links/organic/OrgAcid.htm
Esters
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Within the chain, there is an oxygen atom that is
next to a carbon double bonded to oxygen
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Use oxygen inside of chain as middle point. (Sorta
like an “ether” belly button)
Name both sides around the oxygen atom
 Side with carbon “Alkyl” branch, ends in “yl”
 Side with the double bonded oxygen ends in “oate”
http://www.kentchemistry.com/links/organic/esters.htm
Amines
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Have an “amine” group containing nitrogen.
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Use address

Ends in “-amine”
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Important Example: Amino Acid
http://www.kentchemistry.com/links/organic/amines.htm
Amides
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Also have a nitrogen atom, but it is next
to a carbon double bonded to oxygen.
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End in “amide”.
http://www.kentchemistry.com/links/organic/amide.htm
Organic Reactions
Combustion
Burning or oxidation of a hydrocarbon.
 Needs O2
 Produces CO2 and H2O
 Always EXOTHERMIC
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If not enough O2 present, you can get
“incomplete” combustion resulting in
carbon monoxide (CO) and soot (C).
http://www.kentchemistry.com/links/organic/combustion.htm
Fermentation

Makes ALCOHOL!!!
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Sugar is metabolized by yeast enzymes to
make ethanol and CO2
http://www.kentchemistry.com/links/organic/Fermentation.htm
Substitution
Happens with ALKANES
 One hydrogen atom comes off and is
“substituted” for another atom.
 Results in TWO products
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Ex: Halogen Substitution
http://www.kentchemistry.com/links/organic/Substituition.htm
Addition
ALKENES and ALKYNES.
 Add atoms without removing hydrogen
 Double or triple bond “opens up”
 Two atoms “add on” for each broken bond
 Results in ONE product.
 Ex:
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Halogen Addition
 Hydrogenation
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http://www.kentchemistry.com/links/organic/Addition.htm
Polymerization
Joining together of many individual “monomers” to
make a “polymer”.
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Ex: Synthetic Polymers
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Nylon
Rayon
Polyethelene
Polystyrene (styrofoam)
Polyester
Ex: Natural Polymers
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DNA/RNA
Starch, Cellulose
Proteins
http://www.kentchemistry.com/links/organic/polymers.htm
http://www.kentchemistry.com/links/organic/polymersswf.htm
Types of Polymerization

Condensation Polymerization
Remove water to join monomers
 Ex: Amino Acids joining to make “peptide” bonds
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Addition Polymerization
Open up double/triple bonds to join monomers
 Happens to alkenes/alkynes
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http://www.kentchemistry.com/links/organic/polymerization.htm
Cracking
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Breaking of long hydrocarbon chains into
smaller ones.
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Often used on long chain hydrocarbons
found in petroleum to make them into
more usable fuels.
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Usually involves a catalyst
http://www.kentchemistry.com/links/organic/cracking.htm
Fractional Distillation

Separation of a petroleum mixture by
differences in Boiling Point temperature.
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Most compounds in petroleum are nonpolar hydrocarbons.
Larger chains = stronger VDW = higher BP
Smaller chains = weaker VDW = lower BP
http://www.kentchemistry.com/links/organic/Fractional.htm
***Esterification***

Dehydration synthesis (water is removed to
join molecules)
Alcohol + Organic Acid
Ester + Water
Ester molecules often have nice odors
 Fats are a type of ester made of glycerol and
3 fatty acid chains

http://www.kentchemistry.com/links/organic/esterfication.htm
Saponification
(Making Soap)
Soap molecules are long molecules that
are nonpolar at one end and polar at the
other end.
 Can bring oil and water together

Ester + Base
http://www.kentchemistry.com/links/organic/saponification.htm
Soap + Glycerol