functional groups 18.2. functional groups any element/compound added to a parent chain that effect...
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Functional Groups18.2
Functional Groups• Any element/compound added to a parent chain that
effect its chemical behavior– Substituted hydrocarbon
• Functional groups you must learn:1) Double bonds (Alkenes)2) Triple bonds (Alkynes)3) Halogens4) Alcohols5) Carboxylic Acids6) Esters7) Ethers8) Ketones/Aldehydes9) Amines/Amides
Writing Functional Groups• R symbol of any hydrocarbon• R’ symbol for a second
hydrocarbon; maybe the same as R or may be different
• X symbol of any element within a certain group
• When oxygen is connected to carbon with a single bound -O-
• When oxygen is connected to carbon with a double bound -CO- -C=O-
Halogenated Compounds• Hydrocarbon + a Halogen• R-X; X= F (floro), Cl (cloro),
Br (bromo), or I (iodo)• High density; often used in
solvents and refrigerants• Chlorofluorocarbons
(CFCs) used in aerosol cans and air conditioners (Freon) but have been shown to remove Ozone (O3) from the atmosphere
2-bromopentane
1-chloromethylcyclohexane
Alcohols• Hydrocarbon + Hydroxyl
Group• R-O-H• Polar molecules, high
boiling points, water-soluble
• Solvents, disinfectants, antifreeze, etc…
• Ethanol used in many products that kill bacteria; produced by adding water to Ethene gas
• Drop last “e” of any hydrocarbon and add “-ol”
2-butanol
trans-2-pentanol
2-methyl-2-butanol
Carboxylic Acids• Hydrocarbon + Carboxyl Group• R-COOH; First O is double
bonded to Carbon which also has a Hydroxyl group
• Acidic, strong odors, water-soluble
• Vinegar, toxins, spoiled dairy• Drop last “e” and add “-oic acid”• Pheromones carboxylic acids
used by living things to communicate to each other; strong smells can travel distances and express emotions/states of being
Methanoic acid
Ethanoic acid
Esters• Hydrocarbon + Carboxylic
group + a second Hydrocarbon
• R-COO-R’• Strong aromas, volatile• Scents in perfumes, back-
bone of DNA, fat storage in cells
• Carboxylic group is parent chain; drop “e” + “oate”
• R’ is treated like a side group
methyl methanoate
ethyl ethanoate
phenyl ethanoate
Ethers• Hydrocarbon + Hydroxyl Group
+ a second Hydrocarbon• R-O-R’• Unreactive, insoluble in water,
volatile• Anesthetics (pain killer),
Dissolving fats• Name both hydrocarbons as
side groups and then add “ether”
• Diethyl ether effective anesthetic because is dissolves through plasma membrane
1,1-dimethylethyl methyl ether
1,2-dimethylbutyl ethyl ether
methylcyclohexyl methyl ether
Ketones and Aldehydes• Aldehyde Hydrocarbon +
Carbonyl Group– R-CO-H
• Ketone Carbonyl Group + 2 hydrocarbons– R-CO-R’
• Very reactive, specific odors• Solvents, plastics and adhesives
(glue)• Aldehyde drop last “e” + add
“-al”• Ketone drop “-ane”, add
position number, add “-one”
ethanal phenylethone
cyclohexanal 2-methyl-3-pentone
Amines and Amides• Amines Hydrocarbon +
Amino group – R-NH2
– Basic, ammonia odor• Amide Hydrocarbon +
Carbonyl and Amino Groups– R-CO-NH2
– Neutral• Solvents; Amino acids;
Proteins; hormones• Amines drop “e”, add
position number, add “-amine”• Amide drop “e” + “-amide”
N-methylethanamine
N,N-dimethylmethanamide
Creating Polymers• Polymers are long chains
of repeating units (monomers)
• Names of polymers:StarchCelluloseDNAProteinTeflon• Monomers are joined
through various reactions based on their structure
NucleotidesGlucose
Glucose
TetrafluoroethyleneAmino acids
Polymerization Reactions• Addition Reaction:– Monomers are added to
growing polymers– Often a double bond is
broken as Carbon connect
• Condensation Reaction:– Monomers units with H
atoms and hydroxyl groups (-OH) build polymers
– H atom and –OH break away to make H2O
Rubber and Oils• Cross-linking:– Various polymers are heated
together which allows many connecting points
– The more connection points the stronger the rubber
• Fractional Distillation:– Longer polymers have higher
boiling points– Oils can be separated by
boiling them together; high density oils will remain on the bottom while low density oils move towards the top
Breaking Down Polymers• Cracking:– Break large polymers into
monomers or smaller polymers using a catalyst
– Can convert alkane polymers into alkene monomers
• Recycling plastics:– Thermoplastics can be
melted down to form new plastics from a liquid polymer
– Thermosetting plastics cannot be melted down easily because of crosslinking
– Causing landfill problems
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