Chapter 25

Organic Chemistry

Organic Chemistry

• Organic Chemistry:– The chemistry of Carbon compounds

• Hydrocarbons:– Organic compounds that contain

Hydrogen and Carbon only.

Carbon can form 4 covalent bonds

C

Covalent bond:2 e- shared between two nonmetals.

Represented by a “─”.

Hydrocarbon Prefixes:IUPAC: International Union of Pure and Applied Chemistry Hydrocarbon prefixes

meth Ceth C-Cprop C-C-Cbut C-C-C-CPent C-C-C-C-Chex C-C-C-C-C-Chept C-C-C-C-C-C-Coct C-C-C-C-C-C-C-Cnon C-C-C-C-C-C-C-C-Cdec C-C-C-C-C-C-C-C-C-C

mosquitoseatpeople’sblood

meth = 1 carbon eth = 2 carbons prop= 3 carbons but = 4 carbons

Memory device

Types of formulas (Octane)Molecular

Structural

Condensed Structural

CH3 ─ CH2 ─ CH2 ─ CH2 ─ CH2 ─ CH2 ─ CH2 ─ CH3

Condensed CH3 CH2 CH2 CH2 CH2 CH2 CH2 CH3

orCH3 (CH2 )6 CH3

C8H18

CarbonSkeleton

C ─ C ─ C ─ C ─ C ─ C ─ C ─ C

(4 covalent bonds “─” per C)

H’s are assumed

Types of hydrocarbons• Alkanes:

– All carbon-carbon single bonds.

– Name ends in _____ane

(Saturated hydrocarbon)

Propane

C C C

H H H

H

HHH

H

Prop- = 3

C

H

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

H1 2 3 4 5 6

Hex- = 6

Hexane

Unsaturated hydrocarbons• Alkenes:

– Contains at least one carbon=carbon double bond.

– Name ends in _____ene

(Unsaturated hydrocarbon)

Propene

C C C

H H

H

HH

H

Prop- = 3

C

H

H

H

C

H

H

C

H

C

H

C

H

H

H1 2 3 4 5

Pent- = 52-pentene

Unsaturated hydrocarbons• Alkynes:

– Contains at least one triple bond.

– Name ends in _____yne

(Unsaturated hydrocarbon)

Ethyne(acetylene)

C C HH

eth = 2

1 2 3 4

But- = 42-butyne

HC

H

H

CCC

H

H

H

Branched-Chain Alkanes

3-methylbutane

Parent chain: Longest continuous carbon chain

Substituent: Branch off the parent chain substituted for H.

1 2 3 4

Alkyl groups: attached carbon chains- methyl, ethyl…

C

H

HH

HC

H

H

C

H

C

H

H

C

H

H

H 1234

2-methylbutane

butane2-methylbutane

Branched-Chain Alkanes

Identifysubstituentgroups

Freon molecule: (CFC’s contribute to ozone depletion)

1 2

Halide: attached halogen family elements-

Cl

FC

F

C

Cl

F

Cl

Chlorine is called Chloro

ethane1,1,2-trichloro-1,2,2-trifluoroethane

Fluorine = fluoro, -F

Chlorine = chloro, -Cl

Bromine = bromo, -Br

Iodine = Iodo, -I

Fluorine is called fluoro

Parent chain is last word.

Substituent groups are named alphabetically

IsomersIsomer: Same molecular formula.

C

H

HH

HC

H

H

C

H

C

H

H

C

H

H

H

2,2-dimethylpropane

Pentane

2-methylbutane

C

H

H

H

C

H

H

C

H

H

C

H

H

C

H

H

H

C

H

HH

HC

H

H

C

H

C

H

H

C H

H

H

C5H12

C5H12 C5H12

Different structural formula.

Cis and Trans Isomers• Cis Isomer:

Cis-3,4-dibromo-3-hexene

1 2 3 4 5 6C

H

H

H

C

H

H

C

Br

C

Br

C

H

H

C

H

H

H

C

H

H

H

C

H

H

C

Br

C

Br

C

H

H

C

H

H

H

C

H

H

H

C

H

H

C

Br

C

Br

C

H

H

C

H

H

HTrans-3,4-dibromo-3-hexene

1 2 3 4 5 6

• Trans Isomer: