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Organic Chemistry
Organic Compounds
• Def: Cmpds that are contain mostly carbon and hydrogen (millions)
Ex) plastics, foods, fabrics • Inorganic cmpds – derived from nonliving
things
General Characteristics of Organic Cmpds
• Major diff in organic vs inorganic• inorganic – formed from ionic, covalent, or coordinate
covalent bonds• Organic – formed from covalent bonds • Generally non-polar
insoluble in H2O
soluble in nonpolar solvents (hexanes, benzene)
• Nonelectrolytes (no ions dissociate)
General Characteristics of Organic Cmpds
• Weak intermolecular forces of attraction– London Dispersion forces only (low MP and BP,
high vapor pressure)
• Slow to react (strong covalent bonds)• Major natural resource
Ex) petroleum, coal, natural gas
Structural formulas
• Def: show bonding arrangement of atoms• Carbon has 4 bonding sites• Draw Lewis dot diagram
Methane
Structural formulas
• The 4 bonds of carbon are pushed to the 4 corners of a tetrahedron
• Carbon forms so many diff cmpds because it can bond to itself, by forming– single bonds– double bonds– triple bonds
Saturated compounds
• Def: organic compounds in which all carbon to carbon bonds are single bonds
Ex) ethane propane
Unsaturated Cmpds
• Def: organic cmpds in which at least one Carbon to Carbon bonds is a double or triple bond
Ex) ethene propene
Ethyne propyne
Homologous Series of Hydrocarbons
• Homologous series – grp of organic cmpds that have similar properties and related structures
– hydrocarbons – cmpds containing only carbon and hydrogen
Alkane series
• Def: grp of hydrocarbons which contain carbon atoms linked by single bonds
• Alkanes are saturated cmpds•
Alkane series
• Naming: prefixes are used to relate the # of carbons in the cmpd
• (Table P)meth - hex- eth - hept - prop - oct- but - non - pent - dec-
• - all end in suffix -ane
• Pentane (C5H12)
• General formula (CnH2n+2)
Isomers
• cmpds that have the same molecular formula, but different structural formulas
• isomers represent different compounds with different chem and physical properties
Isomers
• Isomerism begins with butane, C4H10
Naming isomers
• system is based on the longest continuous chain of carbon atoms
• number the longest carbon chain so that the attached group gets the lowest possible #
• branch is named using the # of Carbons prefix,• followed by – yl• name ends in longest carbon chain name
2 methyl propane
Practice: Name the following
Write a structural formula for the following
4-ethyl decane
If a halogen is attached to the C chain, use the following prefixes
Cl – chloro
F – flouro
Br – bromo
I - iodo• number the halogen
Practice
1 – chloropropane 2 – chloropropane 1,2 – dibromopropane 1,1 – dichlorobutane
Alkenes
• a homologous series of unsaturated hydrocarbons which contain one double bond
• General Formula: CnH2n
• prefixes remain same• end in –ene
Alkenes
propene
Isomers of alkenes
1- butene, C4H8 2-butene
Alkynes
• unsaturated hydrocarbons that contain at one triple bond
• General Formula: CnH2n-2
• - end in -yne
• Isomers of alkynes, named for the position of the triple bond
Alkynes
1-butyne, C4H6 2- butyne
Other Organic Compounds (table R)
• Functional Groups• atoms or groups of atoms that give certain
characteristics to an organic molecule (determine how a molecule will react)
Halides
• Def: cmpds in which a halogen atom (F, Cl, Br, or I) replaces a hydrogen on from an alkane.
• on long carbon chains use a number to note the location of the halogen on the carbon chain
Ex) CH3Cl CH3CH2Br
Chloromethane Bromoethane
Alcohols
• contain the functional grp: -OH• (not a hydroxide ion)• ex) R – OH• R represents some carbon chain • Naming: named for the parent alkane chain,
replace last e with -ol
Draw the following:
CH3OH – methanol CH3CH2OH – ethanol
3- pentanol
Ethers
• contain functional grp C - O – C
• General formula: R – O – R • Where the R grps do not have to be the same
• Naming: the RO in the group is the alkoxy group
CH3OCH3 CH3CH2OCH3
Diethyl ether
Organic Acids (carboxylic acids)
• Contain the functional grp: -COOH• Draw actual orientation.
• General formula: R- COOH• Name: name for # of Carbons use alkane
name drop –e and and add – oic acid.
HCOOH CH3COOH
propanoic acid
Amines (considered derivatives of ammonia)
– Functional Grp : - NH2
– General Formula: R – NH2
• R2 – NH
• R3 – N– Naming: name the alkane group to which the
amine is attached• drop the –e ending and add amine
CH3NH2 CH3CH2NH2
2-propanamine
Aldehydes
–contains the functional group:
O R – C – H
– Name: use alkane name for the carbon chain (including carbon attached to the Oxygen) • drop –e and add – al
=
methanal pentanal
ethanal
Ketones
– contain the functional group:
– Name: use alkane name for longest carbon chain• drop –e ending, add - one • number the carbon in which the doublely bonded
oxygen is located
butanone propanone (acetone) 2-pentanone
Amides
• contain the functional grp: O
R- C or RCONH2
NH2
Naming: name the longest carbon chain as you would an alkane drop the –e and add amide
=
_
ethanamide N, N dimethylamide
- N’s denote the
methyl grps attached to the
nitrogens
Do Now:
Identify whether the following are saturated or unsaturated:
C5H10 C4H10
C3H4 C7H16
Esters• contain the functional grp:
OR - C O - R
• Name: names are derived from the alcohol and the acid from which it
is formedportion from the alcohol comes 1st (this is R’)portion from the acid comes 2nd using the alkane name, dropping the –e and adding -
oate
=
_
ethyl pentanoate. ethyl ethanoate
Amino Acids
• Contain both the amino and the organic acid functional group.
• Do not need to name
Organic Reactions
Combustion Reactions of Alkanes
• C3H8(g) + 5O2(g) ----> 3CO2(g) + 4HOH(g)
• 2C4H10(g) + 13 O2(g) ----> 8CO2(g) + 10HOH(g)
Addition Reactions
- The addition of one or more atoms or groups of atoms across a double or triple bond (unsaturated hydrocarbons)
CH CHCH H CH CH CHcatalyst2 3 2 3 2 3
propene propane
Halogenation
CH2=CHCH2CH2CH3 + Br2 ---> CH2BrCHBrCH2CH2CH3
1-pentene 1,2-dibromopentane
Hydrogen AdditionHydrogenation
C2H4(g) + H2(g) ---> C2H6(g)
unsaturated saturated
Substitution Reactions for Alkanes
•Primarily where halogen atoms replace hydrogen atoms on saturated hydrocarbons.
CHCl Cl CCl HClh3 2 4
Esterification
Acid + Alcohol → Ester + water
+ CH3COOH
Do Now: Identify the type of reaction that occurs between the following
compounds and name the products formed.
Butanol + Butanoic acid →
Saponification Reaction:
Fat + strong base Soap + Glycerol
NaOHKOH
O HC17H35-C-O-C-H + NaOH
OC17H35-C-O-C-H + NaOH
OC17H35-C-O-C-H + NaOH
H
Fat Lye (Triglyceride)
O H
C17H35-C-ONa H-C-OH
OC17H35-C-ONa + H-C-OH
OC17H35-C-ONa H-C-OH
H
Soap! Glycerol
How does it happen?? O• Break the ester linkages C – O- by
hydrolyzing the bonds between the carbon backbone and the fatty acid chains.
• (Reversal of esterification reaction)
• Form the sodium salt of a fatty acid (soap) and a trihydroxy alcohol (glycerol).
zymaseC6H12O6 2 C2H5OH + 2 CO2
The basic fermentation reaction:
Polymers
• . . . are large, usually chainlike molecules that are built from small molecules called monomers.
• Monomer PolymerEthylene PolyethyleneVinyl chloride Polyvinyl
chlorideTetrafluoroethylene Teflon
Types of Polymerization
•Addition Polymerization: monomers “add together” to form the polymer, with no other products. (Teflon)
•Condensation Polymerization: A small molecule, such as water, is formed for each extension of the polymer chain. (Nylon)