Download Unit 15 Organic Chemistry Notes

Organic Chemistry!!!
Chapters 22, 23 and 24
Organic Chemistry
The study of carbon and carbon
compounds
MUCH more abundant than inorganic
compounds
BONDING
Organic Compounds bond covalently
Share electrons
Form molecules
MORE BONDING
Carbon atoms bond to one another in:
Chains: C-C-C-C-C-C
Rings:
Networks:
Even More Bonding
Carbon atoms have 4 valence electrons
EN=2.6 (forms mostly covalent bonds)
Shares 4 electrons with other atoms to
attain octet
Types of Covalent Bonds
Carbon atoms may form:
Single bonds
Double bonds
Triple bonds
Structural Formulas
Represents the arrangement of atoms in a
compound
Indicates bonding pattern and shapes
CH4
CH3OH
CH3CH2CH2OH
Tetrahedral shape-CH4: 4 bonds spread out
to the 4 corners
ISOMERS
Compounds with same molecular
formula, but different structural
formulas
Same # and type of atoms, different
arrangement (bonding patterns
different)
ISOMERS
C3H6O (molecular formula)
CH3COCH3
CH3CH2CHO
(structural formulas)
HYDROCARBONS
Compounds that contain only C and H
atoms
Saturated: contain only single bonds
Unsaturated: contain at least 1
multiple bond (double or triple)
Homologous Series of
Hydrocarbons
TABLE Q
Group of organic compounds with
similar properties and related
structures
Homologous Series
The formulas of members of a h. s.
differ from each other by some
common increment
As molecular size increases,
increase weak imf, increase b.p.,
increase f.p. (harder to melt)
ALKANES
Single bonds only (saturated)
Table Q: CnH2n+2
Prefix: # of carbons in longest chain
(Table P)
Ending: -ane
Isomers show up starting with C4H10
butane
ALKENES
One double bond between carbons
(unsaturated)
Table Q: CnH2n
Prefix: Table P (# of C in longest chain)
Ending: -ene
Position of the double bond may vary
(isomers)
Alkenes
Longest chain is numbered, starting at
end closest to double bond
The lower # of C with double bond
precedes the name of the hydrocarbon
ALKYNES
One triple bond between carbons
(unsaturated)
Table Q: CnH2n-2
Prefix: Table P (# C in longest C chain)
Ending: -yne
Position of the triple bond may vary
(isomers)
Alkynes
Longest chain is numbered, starting at
end closest to triple bond
Lower # of the C with triple bond
precedes the name of the hydrocarbon
Other Organic CompoundsTable R
Replace 1 or more hydrogen atoms
with other element or group
Replacement is called a functional group
HALIDES (Group 17)
R-X
Replace H in a hydrocarbon with
halogen
Halogen name is shortened to end in -o
There can be more than 1 halogen
added to a hydrocarbon (replace more
than 1 H)
Prefixes to indicate number
ALCOHOLS
Functional group: -OH (R-OH)
-OH is alcohol in organic, base in
inorganic
Alcohol: does not form hydroxide ion in
solution; not an ionic compound but a molecule
Naming Alcohols
Number of C attached to it (if 3 or more
C)
Name hydrocarbon first
Replace final -e with -ol
Classes of alcohols:
Monohydroxy: one -OH group
Dihydroxy: two -OH groups
Trihydroxy: three -OH groups
1-propanol
Ethers
Functional Group: -O- ; R1-O-R2
Diethyl ether (solvent and anesthetic)
C2H5OC2H5
Methyl ethyl ether
CH3OCH2CH3
diethylether
Methyl ethyl ether
ALdehydes
H
Functional group: -C=O
Naming: replace the -e of hydrocarbon
with -al
Only one available bonding site, usually
found at end of chain
Methanal (formaldehyde)
ketones
Naming: replace the ending -e with
-one
Simplest ketone is when R1 and R2 are
methyl groups (-CH3)
Ketones are isomers of aldehydes
(ketones have 2 R groups, aldehydes 1
R)
ketONEs
Propanone (acetone)
OrganIC ACID
Functional Group: -COOH
To name organic acids
Replace ending -e with -oic acid
Methanoic acid:
Ester
COOCR’ is named first (group attached to the
-O-), -e is replaced with -yl
R is named next (group attached to -C)
-e is replaced by -oate
Methyl ethanoate
Amine
Naming: drop the -e and replace with
-amine
Amides
Combines a carbonyl (double bonded
oxygen) and an amine on the same C.
Amides
Naming: replace -e with -amide
General Characteristics of
Organic Compounds
molecular compounds (contrast with
ionic compounds)
NONPOLAR (mostly)
Few dissolve in water (polar)
Vinegar (acetic acid)
Various sugars and alcohols (all have -OH
like water)
More characteristics
Nonelectrolytes
Not ionic
COOH (organic acids) are weak electrolytes
Low melting points (weak IMFs)
Slow reaction rates
High Ea needed
Catalysts used
Covalent bonds are strong (harder to break)
Organic Reactions
Organic reactions occur at much slower
rates than inorganic reactions
In an organic reaction, the functional
groups are usually involved
TABLE R!!!
Combustion
Saturated hydrocarbon + O2  CO2 +
H2O + heat
Energy derived by combustion and
cellular respiration
Oxidation reactions (oxygen involved)
Substitution
Occurs in saturated hydrocarbons
(alkanes)
Replace a hydrogen with another
element or group
More than 1 product is typical
Substitution
Ethane + bromine  bromoethane +
hydrogen bromide
C2H6 + Br2  C2H5Br + HBr
Addition
Adding two or more atoms to C-atoms
in unsaturated hydrocarbons
Usually saturates the bond  makes a
single bond
Takes place more easily than
substitution reactions
Unsaturated compounds more reactive
than saturated compounds
Addition continued
Triple bonds (alkynes) more reactive
than double bonds (alkenes)
Reactivity: alkynes > alkenes > alkanes
Addition of H= hydrogenation
Requires a catalyst and elevated
temperature
“partially hydrogenated oils”
Characterized by the formation of a
single product
Fermentation
Molecules broken down
Alcohol production (CO2 made alsocarbonation)
Usually associated with living organisms
Yeast
Enzymes serve as catalysts
Fermentation Example
Fermentation of Glucose
Zymasemade by
yeast
Esterification
Organic acid + alcohol  ester + water
Esters have a first and last name (R’ and
R)
R’= first name: alcohol name with -yl ending
R= last name: organic acid name with -oate
ending
Example: ethanoic acid + methanol --> methyl
ethanoate + water
Esters
Are responsible for aromas
Fruits, flowers, leaves
Lipids (fats and oils) are esters
Made from glycerol and fatty acids
Compared to inorganic process of
neutralization
(Acid + Base  salt + water)
Saponification
Making soap
Animal fat + base  soap + glycerol
Hydrolysis of fats (complex esters) by
bases
Break apart esters
Reverse of esterification
Break esters into acid and alcohol
Polymerization
Make a long chain (polymer) by
bonding smaller chains (monomers)
Plastics, nylon, rayon, proteins, starches,
cellulose
Two types of polymerization:
Condensation
Addition
Condensation
Bond monomers by dehydration
(removing water)
Monomer + monomer  polymer +
H2O
Addition
Join monomers of unsaturated
compounds by “opening” a multiple
bond of the carbon chain