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Chapter 22, 23

Organic Chemistry

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Organic Chemistry

Organic chemistry • The study of C-containing cpds• Structures and rxns

• Exceptions: oxides of C, carbonates, hydrocarbonates (inorganic)

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Millions and Millions of Organic Cpds

Carbon • has 4 valence e- (group IV)

• can bond (4 covalent bonds) to as many as 4 other atoms at once,

• can form C-chains (up to several thousand C) and rings of C

• → endless variety of cpds.

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• can bond strongly to elements such as O and N, halogens

• form double and triple bonds.

Millions and Millions of Organic Cpds

• millions of organic cpds

• classified into groups of cpds that have similar structures and properties.

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Hydrocarbons

Hydrocarbons• a group of organic cpds containing only H and C

Hydrocarbons

Saturated hydrocarbons• alkanes• all single bonds

−C−

Unsaturated hydrocarbons• alkenes—with

double bond −C=C−

• alkynes—with triple bond −C≡C−

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Saturated Hydrocarbons

Saturated hydrocarbon: (alkanes) • A hydrocarbon in which all the C atoms are

connected to each other by single bonds.

−C−C − C − C − C − C − C − C − C − C−

covalent

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Saturated Hydrocarbons

Uses of Alkanes

• the simplest hydrocarbons. (saturated)

• fuels e.g. methane (in town gas), propane (bottled fuel for BBQ), butane (lighter), gasoline

• as solvents in paint removers, glues, and other products.

• Other uses

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Alkanes

• The C in an alkane can be arranged in a chain or a ring.

• both chains and rings can have branches of other C chains attached to them.

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• Some alkanes have branched structures.

Alkanes

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• The condensed structural formula for propane can be written as CH3CH2CH3.

Alkanes

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Alkanes

CnH2n+2

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Energy source in the U.S.

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Fractionating column

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Fractions from Crude Oils

Fraction Compn of C chain

Boiling range (°C)

Natural gas C1 to C4 Below 20

Petroleum ether C5 to C6 30 to 60

Naphtha C7 to C8 60 to 90

Gasoline C6 to C12 40 to 175

Kerosene C12 to C15 150 to 275

Fuel oils, mineral oil C15 to C18 225 to 400

Petroleum jelly, wax, asphalt

C16 to C24 Over 400

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Unsaturated Hydrocarbons

Unsaturated hydrocarbon• A HC that has 1 or more −C=C− or −C≡C−

bonds• The other bonds are single bonds (−C−)• Alkenes (−C=C−), alkynes (−C≡C−)

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Alkenes

Alkenes

• A hydrocarbon containing 1 or more −C = C− bonds

• Unsaturated

• ending with -ene

• ethene• propene• butene• pentene

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Alkenes

• An unsaturated alkene can be converted into a saturated alkane by adding H to the C=C bond.

• hydrogenation.

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Alkynes

• Another type of unsaturated HC—alkyne, contains a triple bond (−C≡C−) between 2 C atoms.

• ending with -yne.• ethyne, propyne, butyne

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Alkynes

General formula: CnH2n-2

Ethyne C2H2 H—C≡C—H

H

|

Propyne C3H4 H—C—C≡C—H

|

H

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Aromatic Hydrocarbons

Aromatic hydrocarbon

• has a benzene ring

• most of them have distinctive aromas.

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Monomers and Polymers

A Polymer

• a giant molecule formed by covalent bonds

• hundreds or thousands of small individual repeating units (monomers), bonded together in chains.

• Monomers may all be alike, or they may be different.

• Properties of a polymer are different from those of the monomers that formed it.

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Synthetic Polymers

• Polymers are everywhere, making fabrics such as nylon and polyester, plastic wrap and bottles, rubber bands, and many more products you see every day.

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Structure of Polymers

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Structure of Polymers

Cellulose polymer found in the cell walls of plant cells

• monomer : glucose

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Structure of Polymers

• glucose

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Structure of Polymers

Starch

• natural plant polymer

• Monomer: glucose

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Rubber

• used in tires and rubber balls.

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Plastics

plastic ≠ polymer

not all polymers are plastics.

Plastics can be molded into different shapes.

must be heated enough to become liquefied if it is to be poured into a mold.

harden if it is allowed to cool.

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Functional Groups

A functional group in an organic molecule

• an atom or group of atoms that

• always reacts in a certain way (similiar chem properties)

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Functional Groups: Structure and Function

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Functional Groups

• The symbols R and R′ represent any C chains or rings bonded to the functional group.

• * represents a H atom, C chain, or C ring.

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Some Functional Groups

Compound type General Formula Functional groups

Halohydrocarbons R―X (F, Cl, Br, I) Halogens

Alkanols (Alcohols)

R―OH Hydroxyl e.g. methanol, ethanol

Alkanals(Aldehydes)

O ‖* C ―H

Carbonyl e.g. propanal

Alkanoic acids (Carboxylic acids)

O ‖* C ―OH

Carboxyl

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Cpd type Examples Condensed structural formula

Halohydro-carbon

Bromomethanetrichloromethane

CH3─Br (methyl bromide)CHCl3

Alkanols MethanolEthanolpropanol

CH3OHC2H5OH (CH3CH2OH)C3H7OH (CH3CH2CH2OH)

Alkanoic acid

Ethanoic acidPropanoic acid

C2H5COOH (CH3CH2 COOH)C3H7COOH (CH3CH2CH2COOH)

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Organic Cpds Containing Halogens

halohydrocarbon

• Any org cpd that contains a halogen substituent.

• one H in the methane is replaced by a halogen.

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Chloro-methane

CH3Cl H l H ─ C ─ Cl l H

Dichloro-methane

CH2Cl2 H l H ─ C ─ Cl l Cl

Trichloro-methane

CHCl3 H l Cl ─ C ─ Cl l Cl

Tetrachloro-methane

CCl4 Cl l Cl ─ C ─ Cl l Cl

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Alkanols (Alcohols)

• hydroxyl group (—OH).

• R─OH

Alcohol• An organic cpd in

which a hydroxyl gp replaces a H atom of a HC. Methanol

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Alkanols (Alcohols) CnH2n+1OH

Alkanol Condensed formula

Structural formula

Old name

Methanol

CH3OH H | H − C − OH | H

methyl alcohol

Ethanol

C2H5OH H H | | H − C − C − OH | | H H

ethyl alcohol

Propanol C3H7OH

Butanol C4H9OH

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Methanol(MethylAlcohol)

CH3OH H l H ─ C ─ OH l H

Ethanol C2H5OHCH3CH2OH

H H l l H ─ C ─ C─ OH l l H H

Propanol C3H7OHCH3CH2CH2OH

H H H l l l H ─ C ─ C ─ C ─ OH l l l H H H

Butanol C4H9OHCH3CH2CH2CH2OH

H H H H l l l l H ─ C ─ C ─ C ─ C ─ OH l l l l H H H H

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Alkanoic acids (Carboxylic Acids)

A alkanoic acid:

• an organic cpd that has a carboxyl group.

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Alkanoic Acids (Carboxylic Acids)

*COOH

Methanoic acid (formic acid) HCOOH

Ethanoic acid (acetic acid) CH3COOH

Propanoic acid C2H5COOH

Butanoic acid C3H7COOH

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Methanoic acid

HCOOH O ll H ─ C ─ OH

Ethanoic acid

CH3COOH H O l ll H ─ C ─ C─ OH l H

Propanoic acid

C2H5COOHCH3CH2COOH

H H O l l ll H ─ C ─ C ─ C ─ OH l l H H

Butanoic acid

C3H7COOHCH3CH2CH2COOH

H H H O l l l ll H ─ C ─ C ─ C ─ C ─ OH l l l H H H

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CST problem 1

For the polymer, polyvinyl chloride (PVC), ~CH2CH2CH(Cl)CH2CH(Cl)CH2CH(Cl)~

the repeat unit is

A CH(Cl)

B CH(Cl)CHCH2

C CH2CH

D CH2CH(Cl)

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The End