Z7e Chapter 22 Organic Chemistry Z7e Chapter 22 Organic Chemistry pppp
50 questions on online HW50 questions on online HW
Stop whining!Stop whining!
They’re not too hard (for me)They’re not too hard (for me)
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Z5e 22.1 Alkanes: Saturated HydrocarbonsZ5e 22.1 Alkanes: Saturated Hydrocarbons pppp
Carbon atoms can form 4 bonds Nitrogen atom can form 3 bonds Oxygen atoms can form 2 bonds Hydrogen atoms can form 1 bond Useful to know when building up structures Double and triple bonds count as one
“effective” pair.
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Tr 114 Methane - Tetrahedral sp3 Structure
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Tr 115 Bonding in Ethene & Ethyne
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Isomers
Same molecular formula Same number and types of atoms Different arrangement of atoms
6
Examples of IsomersThe formula C4H10 has two different structures
CH3
CH3CH2CH2CH3 CH3CHCH3
Butane 2-methylpropane
When a CH3 is is used to form a branch, it makes a new
isomer of C4H10.
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Structural Isomers pppp
Compounds that have the same molecular formula, but different molecular structures, are called structural isomers
Butane and 2-methylpropane in previous slide.
Also have different properties, such as b.p., m.p., and reactivity
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Geometric Isomers pppp
There is a lack of rotation around a carbon to carbon multiple bond– has an important structural implication– Two possible methyl arrangements:
1. trans configuration - substituted groups on opposite sides of double bond
2. cis configuration - same side
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Geometric Isomers pppp
Differ only in the geometry of their substituted groups
Like other structural isomers, have different physical and chemical properties
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Geometric Isomers of 1,2-dichloroethene
Cl Cl H Cl C=C C=C H H Cl
H cistrans
Rigid structure so these are isomers with different properties.
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Geometric Isomers of chloroethene? pppp
H Cl H H C=C C=C H H H
Cl Rigid structure BUT both carbons
do NOT have two DIFFERENT groups attached to them.
These are just rotated in space, but are the same.
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Nongeometric versions of 1,2-dichloroeth”ene” pppp
Cl Cl H Cl C--C C--C H H Cl
H Non-rigid structure so these are
NOT isomers. (The 3rd hydrogen on each carbon is not shown)
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Z5e 22.1 Alkanes: Saturated Hydrocarbons
Contain C and H only
Contain single bonds C-C
Have 4 bonds to every carbon (C) atom
Are nonpolar
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Straight-Chain Alkanes
Straight-chain alkanes contain any number of carbon atoms, one after the other, in a chain - meaning one linked to the nextC-C-C C-C-C-C etc.
Names of alkanes always will always end with -ane
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Straight-Chain Alkanes
Combined with the -ane ending is a prefix for the number of carbons
Homologous series - a group of compounds that have a constant increment of change
In alkanes, it is: -CH2-
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Tr 115A Carbon-Atom Chain Prefixes
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Tr 117 Some Alkanes
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Straight-Chain Alkanes Many alkanes used for fuels:
methane, propane, butane, octane As the number of carbons increases,
so does the boiling and melting pt.– The first 4 are gases; #5-15 are liquids;
higher alkanes are solids.
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Tr 117A Straight-Chain Alkyl Groups
How are alkyl groups different from their corresponding alkanes?How are alkyl groups different from their corresponding alkanes?
They have one less hydrogen so they can bond to another atom.They have one less hydrogen so they can bond to another atom.
What would a nine-carbon alkyl group be called?What would a nine-carbon alkyl group be called?
NonylNonyl
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Alkanes 3-ethylpentane 2,3,4-trimethylhexane Since the electrons are shared
equally, the molecule is nonpolar– thus, not attracted to water– oil (a hydrocarbon) not soluble in H2O– “like dissolves like”
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Complete Structural Formulas
Shows the bonds between each of the atoms H H
H C H H C H
H H
CH4 , methane
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More Alkanes
H H Condensed Structural Formulas
H C C H CH3 CH3
H H Ethane
H H H
H C C C H CH3 CH2 CH3
H H H Propane
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Naming Straight-Chain Alkanes
Names recommended by IUPAC - the International Union of Pure and Applied Chemistry– end with -ane, the root part of the name
indicates the # of carbons We sometimes still rely on common
names, some of which are well-known
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Naming Straight-Chain Alkanes
IUPAC names may be long and cumbersome
Common names may be easier or more familiar, but usually do not describe the chemical structure!– Methane is natural gas or swamp gas
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Branched-Chain Alkanes
Branched-chain means that other elements besides hydrogen may be attached to the carbon– halogens, oxygen, nitrogen, sulfur, etc.– any atom that takes the place of a hydrogen
on a parent hydrocarbon (including another carbon) is called a substituent, or the branched part
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Branched-Chain Alkanes A hydrocarbon substituent is called an
alkyl group or sometimes radicals– use the same prefixes to indicate the number
of carbons, but the -ane ending is now -yl methyl, ethyl, propyl, etc.
Gives much more variety to the organic compounds
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Alkyl GroupsBranches on carbon chains H
H C CH3 methyl
H
H H
H C C CH2CH3 ethyl
H H
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Branched-Chain Alkanes pppp
Rules for naming - page 10001. Longest chain is the parent (tricky).2. Number so branches have low # of
carbons.3. Give position number to branch4. Use prefixes if more than one branch5. Alphabetize branches6. Use proper punctuation ( - , )
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Branched-Chain Alkanes Draw 2,3,5-trimethyl hexane (on
board) From the name, draw the structure:1. Find the parent, with the -ane2. Number carbons on parent3. Identify substituent groups; attach4. Add remaining hydrogens
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IUPAC NamesName # carbons Structural Formula
Methane 1 CH4
Ethane 2 CH3CH3
Propane 3 CH3CH2CH3
Butane 4 CH3CH2CH2CH3
Pentane 5 CH3CH2CH2CH2CH3
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Cyclic Hydrocarbons The two ends of the carbon chain
are attached in a ring in a cyclic hydrocarbon– sample drawings on page 1066– named as “cyclo- ____”
hydrocarbon compounds that do NOT contain benzene rings are known as aliphatic compounds
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CycloalkanesCyclopropane CH2
CH2 CH2
CyclobutaneCH2 CH2
CH2 CH2
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Naming Cycloalkanes with Side Groups
Number of Naming side groups
One Side group name goes in front of the cycloalkane name.
Two Number the ring in the direction that gives the lowest
numbers to the side groups.
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Alkane name review Given the alkane name, how can
you draw the structural formula? 1. Find the root word (ending in -ane) in the hydrocarbon name; write the longest hydrocarbon chain to create the parent
2. Number the carbons of this parent chain
3. Identify substituents and attach them
4. Add hydrogens as necessary
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Naming Review What is the name of the alkyl group
that contains three carbon atoms?
Name: CH3CH2C(CH3)3
A structural isomer of pentane is a) 2,2-dimethylpropane or b) benzene
propyl
2,2-dimethylbutane
a
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Z5e 22.2 Alkenes & Alkynes
Multiple bonds can also exist between the carbon atoms
Hydrocarbons containing carbon to carbon double bonds are called alkenes C=C C-C=C
Called “unsaturated” if they contain double or triple bonds (alkynes)
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Tr 118 Structures of Alkenes
Name ends in “-ene”
Why are these called unsaturated?
Less than 4 “things” on some of the carbons.
Note the cis and trans isomers.
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Naming Alkenes pppp
Find longest parent that has the double bond in it
New ending: -ene Number the chain, so that the
double bond gets the lower number Name and number the substituents Samples on page 1005
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Alkynes Hydrocarbons containing carbon to
carbon triple bonds called alkynes -C C- Alkynes are not plentiful in nature Simplest is ethyne - common name
acetylene (fuel for torches)
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Z5e 22.3 Aromatic Hydrocarbons
Benzene is a six-carbon ring.– exhibits resonance, due to location of
the double and single bonds
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Aromatic Compounds and Benzene
Aromatic compounds contain benzene. Benzene, C6H6 , is represented as a six
carbon ring with 3 double bonds. Two possible ways to show benzene in this
form. HH
H
HH
HH
H
HH
H
H
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Benzene Structure
The structures for benzene can also be written as a single structure where the resonating double bonds are written as a circle within the ring.
Benzenestructure
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Tr 119 Resonance Structures of Benzene
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Tr 118A Representations of Benzene
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Aromatic Hydrocarbons Benzene derivatives possible:
– methylbenzene, 3-phenylhexane, ethylbenzene
Benzene derivatives can have two or more substitutents:– 1,2-dimethylbenzene– 1,3-dimethylbenzene– 1,4-dimethylbenzene
Can use ortho for 1,2; meta for 1,3; and para for 1,4
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Tr 119A Structural Formula for Aspirin
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Naming Aromatic Compounds pppp
Aromatic compounds are named with benzene as the parent chain. One side group is named in front of the name benzene.
methylbenzene chlorobenzene (toluene)
CH3 Cl
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Naming Aromatic Compounds pppp
When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) are also used.
CH3
CH3
Cl
Cl
Cl
CH3
1,2-dimethylbenzene 1,3-dichlorobenzene 1-chloro-4-methylbenzene(ortho-dimethylbenzene) (meta-dichlorobenzene) (para-chloromethylbenzene)
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Some Common Names pppp
Some substituted benzene rings also use a common name. Then naming with additional more side groups uses the ortho-, meta-, para- system.
CH3
Cl
CH3 OH
Toluene meta-chlorotoluene phenol(Methylbenzene) (meta-chloromethylbenzene) (hydroxybenzene)
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Review How many carbons are in a molecule of
benzene? Six What is the name of the alkane having 5
carbons? Pentane What is the substituent in the following
compound: CH3CH2CH2CH2Cl Cl
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An Interlude: The Petrochemical Industry
Fossil fuels provide much of the world’s energy
Natural gas and petroleum contain mostly aliphatic (straight-chain) hydrocarbons
Natural gas is an important source of alkanes of low molecular mass
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Natural Gas Natural gas is prized for combustion,
because with adequate oxygen, it burns with a hot, clean blue flame:– CH4 + 2O2 CO2 + 2H2O + heat
Insufficient burning has a yellow flame, due to glowing carbon parts, as well as making carbon monoxide
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Petroleum It is separated by distillation into
fractions, according to boiling pt. Fractions containing higher molar
mass can be “cracked” into more useful shorter chain components, such as gasoline and kerosene– involves catalyst and heat– starts materials for plastics and paints
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Petroleum The compounds found in petroleum
(or crude oil) are more complex than those in natural gas
Usually straight-chain and branched-chain alkanes, with some aromatic compounds also
Crude oil must be refined (separated) before being used
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Petroleum Refinery
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Z5e 22.4 Hydrocarbon Derivatives
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Functional Group Functional group - a specific arrangement Functional group - a specific arrangement
of atoms in an organic compound capable of atoms in an organic compound capable of of characteristic chemical reactionscharacteristic chemical reactions..
The best way to classify organic The best way to classify organic compounds.compounds.
Replaces an “H” in the corresponding Replaces an “H” in the corresponding alkane.alkane.
The symbol “R” is used to represent any The symbol “R” is used to represent any carbon chains or ringscarbon chains or rings
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Z7e 1011 Table 22.4 Common Functional Groups pppp
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Alcohols pppp
Alcohols - a class of organic compounds with an -OH group– The -OH functional group in alcohols is
called a “hydroxyl” group; thus R-OH is the formula
How is this different from the hydroxide ion? The hydroxyl group is covalently bonded to
the R group. Hydroxides have ionic bonding with their cations.
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Alcohols pppp
Common names:–similar to halocarbons: Name the
alkyl group followed by the word alcohol
–One carbon alcohol = methyl alcohol
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Organic ChemicalsAlcoholsAlcohols R-R-OHOH
CHCH33OHOH methanmethanolol
(methyl alcohol)(methyl alcohol)CHCH33CHCH22OHOH ethanethanolol
(ethyl alcohol)(ethyl alcohol)(CH(CH33))22CHOHCHOH 2-propan2-propanolol
(isopropyl alcohol)(isopropyl alcohol)
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Properties of Alcohols
Much like water, alcohols are capable of hydrogen bonding between molecules (polar).–this means they will boil at a
higher temperature than alkanes and halocarbons with a comparable number of atoms
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Properties of Alcohols
Denatured alcohol - means it has been made poisonous by the addition of other chemicals, often methyl alcohol (methanol, or wood alcohol).
As little as 10 mL of methanol has been known to cause permanent blindness, and 30 ml has resulted in death!!!
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Alcohols pppp
Arranged into categories according to the number of R groups attached to the carbon with the hydroxyl–1 R group: primary alcohol–2 R groups: secondary alcohol–3 R groups: tertiary alcohol
Let’s do some examples on the whiteboard (see p. 1077).
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Naming Alcohols pppp
A carbon compound that contain -OH (hydroxyl) A carbon compound that contain -OH (hydroxyl) groupgroup
In IUPAC name, the -e in alkane name is replaced In IUPAC name, the -e in alkane name is replaced with -ol.with -ol.
Parent is the longest chain containing the carbon Parent is the longest chain containing the carbon with the hydroxly attached.with the hydroxly attached.
CHCH4 4 methanmethanee
CHCH33OH OH methanmethanolol (methyl alcohol) (methyl alcohol)
CHCH33CHCH33 ethanethanee
CHCH33CHCH22OH OH ethanethanolol (ethyl alcohol(ethyl alcohol))
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Alcohols pppp
The hydroxyl is given the lowest position number
Alcohols containing 2, 3, and 4 of the -OH substituents are named diols, triols, and tetrols respectively
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More Names of Alcohols pppp
IUPAC names for longer chains number the chain from the end nearest the -OH group.
CH3CH2CH2OH 1-propanol
OH CH3CHCH3 2-propanol
CH3 OH CH3CHCH2CH2CHCH3 5-methyl-2-hexanol
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Name the following alcohols:
Name the following alcohols:A. OH
CH3CHCHCH2CH3
CH3
OHB.
3-methyl-2-pentanol
cyclobutanol
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Some Typical Alcohols OH “rubbing alcohol” CH3CHCH3
2-propanol (isopropyl alcohol)
antifreeze HO-CH2-CH2-OH1,2-ethanediol (ethylene glycol)
OH
glycerol HO-CH2-CH-CH2OH (name?)
Anti-
freez
e
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Halogen Substituents Also known as alkyl halides. Halocarbons - class of organic
compounds containing covalently bonded fluorine, chlorine, bromine, or iodine.
Naming? Name parent as normal, add the halogen as a substituent (or prefix)
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Chlorofluorocarbons (CFCs and the Ozone Layer
Ozone (O3) layer absorbs most of the sun’s harmful radiation.
CFCs - chlorofluorocarbons - are depleting that ozone layer.
CFCs are used as Freons in refrigeration,
air conditioning, and foam insulation. Their use in spray cans is no longer
allowed.
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Chlorofluorocarbons and the Ozone Layer
In the stratosphere, the CFCs first react with the high-energy UV radiation from the sun
UV lightCF2Cl2 CF2Cl + Cl
Freon-12 free radical
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Chlorofluorocarbons and the Ozone Layer
To become stable, the Cl acquires an electron from ozone O3 and produces ClO.
Cl + O3 ClO + O2
The presence of ClO in the atmosphere is an indicator of the disappearance of ozone.Chlorine atoms are eventually regenerated.
ClO + O Cl + O2
Makes it possible for a single chlorine atom to destroy thousands of ozone molecules.
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Ethers pppp
Contain an -O- between two carbon groups Simple ethers named from -yl names of the
attached groups and adding ether. Naming? The two R groups are alphabetized,
and followed by ether Two R groups the same? Use the prefix di.
CH3-O-CH3 dimethyl ether
CH3-O-CH2CH3 ethyl methyl ether
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Aldehydes and Ketones pppp
Review:–alcohol has an oxygen bonded to
a carbon group and a hydrogen–ether has an oxygen bonded to
two carbon groups An oxygen can also be bonded to a
single carbon by a double bond
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Aldehydes and Ketones pppp
The C=O group is called the “carbonyl group”– it is the functional group in both
aldehydes and ketones Aldehydes - carbonyl group always
joined to at least one hydrogen (meaning it is always on the end!)
R C H
O
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Aldehydes and Ketones pppp
Ketones - the carbon of the carbonyl group is joined to two other carbons (meaning it is never on the end)
R C R
O See structures on pp. 1080-1081.
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Aldehydes and Ketones In an aldehyde, an H atom is attached to a
carbonyl group O carbonyl group
CH3-C-H In a ketone, two carbon groups are attached to a
carbonyl group O carbonyl group
CH3-C-CH3
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Naming Aldehydes and Ketones pppp
Aldehydes: identify longest chain containing the carbonyl group, then the -e ending replaced by -al
methanal, ethanal, etc.ketones: longest chain w/carbonyl,
then new ending of -one; number it propanone, 2-pentanone, 3-pentanone
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Naming Aldehydes pppp
IUPAC: Replace the -e in the alkane name -al Common: Add aldehyde to the prefixes form (1C),
acet (2C), propion(3), and butry(4C) O O O
H-C-H CH3-C-H CH3CH2C-H
methanal ethanal propanal (formaldehyde) (acetaldehyde) (propionaldehyde)
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Naming Ketones pppp
In the IUPAC name, the -e in the alkane name is replaced with -one
In the common name, add the word ketone after naming the alkyl groups attached to the carbonyl group O O
CH3 -C-CH3 CH3-C-CH2-CH3
Propanone 2-Butanone (Dimethyl ketone) (Ethyl methyl ketone)Cyclohexanone
O
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Aldehydes and Ketones pppp
Neither can form intermolecular hydrogen bonds, thus a much lower b.p. than corresponding alcohols
Wide variety have been isolated from plants and animals; possible fragrant odor or taste; many common names
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Common Aldehydes and Ketones
Benzaldehyde Cinnamaldehyde Vanillin Methanal (common: formaldehyde)
–40% in water = formalin, a preservative
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Aldehydes and Ketones
Propanone (common: acetone) is a good solvent; miscible with water in all proportions
Why is it a good substance used in nail-polish removers? . . .
Good solvent for nonpolar substances also.
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Ketones
O O
Butter flavor CH3-C-C-CH3 butanedione O Clove flavor CH3-C-CH2CH2CH2CH2CH3
2-heptanone
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More Aldehydes as Flavorings
Benzaldehyde Vanillin Cinnamaldehyde(almonds) (vanilla beans) (cinnamon)
CH=CH CHOCH
O
HOOCH3
CHO
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Review Check
Formula for an aldehyde?
Which would have the highest boiling point? a) propane b) 1-propanol
Name: CH3CH2OCH2 CH3
Phenols are characterized by:
( b )
( diethyl ether )
( an -OH group on a benzene ring )
O
R - C - H
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Review Check Formula for a ketone?
Hydrogen-bonding cannot occur between: a) water-alcohol b) water-alkane
O Name: CH3CCH2CH3
O
R - C - R
( b )
( 2-butanone )
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Learning Check
Classify each as an aldehyde (1), ketone (2) or neither (3).
O
A. CH3CH2CCH3 B. CH3-O-CH3
CH3 O C. CH3-C-CH2CH D.
CH3
O
2
2
3
1
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Carboxylic Acids pppp
Also have a carbonyl group (C=O) like aldehydes and keytones, but is also attached to a hydroxyl group (-OH) = “carboxyl” group
general formula: R-COOH–weak acids (ionize slightly)
Named by replacing -e with -oic and followed by the word acid
methanoic acid; ethanoic acid
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Carboxyl Group pppp
Carboxylic acids contain the carboxyl group on carbon 1. O
CH3 — C—OH = CH3—COOH
carboxyl group
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Carboxylic Acids - look for functional group pppp
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Naming Rules pppp
Identify longest chain (IUPAC) Number carboxyl carbon as 1 (Common) Assign , , to carbon atoms adjacent to
carboxyl carbon CH3
|CH3 — CH—CH2 —COOHIUPAC 3-methylbutanoic acidCommon -methylbutryic acid
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Naming Carboxylic Acids pppp
Formula IUPAC Common alkan -oic acid prefix – ic acid
HCOOH methanoic acid formic acid
CH3COOH ethanoic acid acetic acid
CH3CH2COOH propanoic acid propionic acid
CH3CH2CH2COOH butanoic acid butyric acid
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Tr 123 Fig 21.5 Carboxylic Acid: Citric Acid
How many carboxyls groups does this have?
Three
Why is this acidic?
It can lose a hydrogen ion.
How does it affect the taste of citrus fruits?
Acids give a sour taste.
96
Esters pppp
In an ester, the H in the carboxyl group is replaced with an alkyl group
O
CH3 — C—O —CH3 = CH3—COO —CH3
ester group
97
Esters pppp
General formula: RCOORGeneral formula: RCOOR Derivatives of carboxylic acids, where the Derivatives of carboxylic acids, where the
--OHOH from the carboxyl group is from the carboxyl group is replacedreplaced by an -by an -OROR from an alcohol: from an alcohol:carboxylic acid + alcohol carboxylic acid + alcohol ester + water ester + water
Usually a trace of mineral acid added as Usually a trace of mineral acid added as catalyst (acids are dehydrating agents)catalyst (acids are dehydrating agents)
many esters have pleasant, fruity odors- many esters have pleasant, fruity odors- banana, pineapple, perfumesbanana, pineapple, perfumes
Lab 25 is an ester lab. Lab 25 is an ester lab. See website for See website for special instructionsspecial instructions..
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Esters pppp
Although polar, they do not form hydrogen bonds (reason: there is no hydrogen bonded to a highly electronegative atom)–thus, much lower b.p. than the
hydrogen-bonded carboxylic acids they came from!
99
Naming Esters pppp
Naming? It has 2 words: 1st: Name the alkyl attached to the
single bonded oxygen from the alcohol. 2nd: take the acid name, remove the -oic
acid, add -oate.
O
CH3 CH2 C O CH2 CH3
Ethyl propanoate
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Naming Esters pppp
Name the alkyl from the alcohol –O- Name the acid with the C=O with –ate acid alcohol
O methyl
CH3 — C—O —CH3
Ethanoate methyl ethanoate (IUPAC)(acetate) methyl acetate (common)
101
Some Esters and Their Names
Flavor/OdorRaspberries
HCOOCH2CH3 ethyl methanoate (IUPAC)ethyl formate (common)
PineapplesCH3CH2CH2 COOCH2CH3 ethyl butanoate (IUPAC)
ethyl butyrate (common)
102
Learning CheckGive the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears . . .
O
CH3 — C—O —CH2CH2CH3
103
Solution
O propyl
CH3 — C—O —CH2CH2CH3
propyl ethanoate (IUPAC)propyl acetate (common)
104
Esters in Plants
Esters give flowers and fruits their pleasant fragances and flavors.
Used as flavoring agents.
105
Common Flavors & Odors of Esters
106
Amines pppp
Organic compounds of nitrogen N Classified as primary, secondary, tertiary
CH3 CH3
CH3—NH2 CH3—NH CH3—N — CH3
1° 2° 3°
107
Naming Amines pppp
IUPAC aminoalkane Common alkylamineCH3CH2NH2 CH3—NH —CH3
aminoethane N-methylaminomethane(ethylamine) (dimethylamine)
NH2
|CH3CHCH3
2-aminopropane (isopropylamine) Aniline N-methylaniline
NH2 NH CH3
108
Learning Check
Give the common name and classify if primary, secondary or tertiary:
A. CH3NHCH2CH3 . . .
CH3
| B. CH3CH2NCH3 . . .
ethylmethylamine, 2°
ethyldimethylamine, 3°
109
DNA & RNA contain amines
110
Alkaloids
Physiologically active nitrogen-containing compounds
Obtained from plants Used as anesthetics, antidepressants, and
stimulants Many are addictive
111
Nicotine
N
CH3
Nicotine, leaves of tobacco plant
112
Caffeine
N
N N
NCH3
O
O CH3
CH3Caffeine, coffee beans and tea
113
Z7e 1011 Table 22.5 Common Functional Groups
114
Organic Reactions 4 Types: Substitution, addition,
condensation & elimination. Some (but not all) of this can be
found on page 1003 & 1007 of Z7e.
115
Substitution Reactions pppp
Halogens on carbon chains are readily displaced by hydroxide ions (OH1-) to make an alcohol + a salt:R-X + OH1- R-OH + X1-
116
Substitution Reactions pppp
CH3-I + KOH CH3-OH + KI
CH3CH2Br + NaOH CH3CH2OH + NaBr
Iodomethane Methanol
Bromoethane Ethanol
117
Addition Reactions pppp
Carbon-carbon single bond is not easy to break
In double bonded alkenes, it is easier to break a bond
Addition reaction- substance is added at the double or triple bond location, after it is broken
CH3CH=CHCH3 + H2 CH3CH2CH2CH3
118
Fatty Acid Addition Reaction
119
Saturated vs. Unsaturated Fatty Acids
120
Condensation Reactions pppp
Two molecules combine Acid + Alcohol Ester + water HCOOH + HOCH3 HCOOCH3 + H2O
121
Elimination Reactions pppp
A simple molecule like water or ammonia is removed from an organic molecule.
122
Z7e 22.5 Polymers large molecule formed by joining many
smaller molecules together
Monomer small molecules which are joined
together to form a polymer
123
Addition Polymers
Polymers are giant molecules, not small like the ones studied earlier in this chapter
Examples are plastics Polymer - large molecule formed by
the covalent bonding of smaller molecules called monomers
124
Addition Polymers An addition polymer forms when
unsaturated monomers react to form a polymer–ethene will form polyethylene,
see next slide.–polyethylene is easy to clean,
chemically resistant - milk bottles, plastic wrap, refrigerator dishes
125
Addition Polymers
126
Addition Polymers
CH = CH2 |R
polyethylene R => Hpolypropylene R => CH3
polyvinylchloride R => Clpolystyrene R => benzene ring
127
Addition Polymers
Vulcanization - cross-linking of polyisoprene molecules that occurs when heated with sulfur.
Charles Goodyear accidentally discovered this and used it to make synthetic rubber for tires, etc.
128
Condensation Polymer pppp
Polymer formed by molecules of two different compounds joining to form the large molecule
One compound usually has an amine functional group
Other molecule has carboxylic acid functional group
Split out water molecule to form peptide linkage O H
C N
129
Condensation to Nylon pppp
Monomers - hexanediamine & adipic acid
Polyamide - amide (peptide) is in the polymer
Nylon 66 - each monomer has 6 carbon atoms
Polyester is another type of condensation polymer
130
Nylon 66 being wound on a stirring rod
