Chapter 7
Carbon and Organic
Compounds
Organic Chemistry
 Organic originally meant chemicals
that came from organisms
 1828 German chemist Friedrich
Wohler synthesized urea in a lab
 Today, organic chemistry is the
chemistry of virtually all compounds
containing the element carbon
Organic Compounds
 Contain
carbon
 Have
covalent bonds
 Have
low melting points
 Have
low boiling points
 Burn
in air (oxygen)
 Are
soluble in nonpolar solvents
 Form
large molecules
Organic Chemistry and
Hydrocarbons
 Over a million organic compounds,
with a dazzling array of properties
 Why so many? Carbon’s unique
bonding ability!
 Let’s start with the simplest of the
organic compounds: Hydrocarbons
Hydrocarbons
 Hydrocarbons contain only two
elements: hydrogen and carbon
 simplest hydrocarbons called
alkanes, which contain only single
covalent bonds
 methane (CH4) with one carbon is the
simplest alkane; also known as
swamp gas; main component of
natural gas.
Complete Structural Formulas
Show the bonds between each of the
atoms
H
H

HCH
H
C

H
H
CH4 , methane
H
alkanes
Carbon has 4 valence electrons,
thus forms 4 covalent bonds
 not only with other elements, but also
forms bonds WITH ITSELF.
Ethane (C2H6) is the simplest alkane
with a carbon to carbon bond
More Alkanes
H
H
H
H
C
C
H
H
Condensed Structural Formulas
H
CH3
CH3
Ethane
H
H
H
C
C
C
H
H
H
H
CH3 CH2 CH3
Propane
Straight-Chain Alkanes
 Straight-chain alkanes contain any
number of carbon atoms, one after
the other, in a chain - meaning one
linked to the next
C-C-C
C-C-C-C
etc.
Straight-Chain Alkanes
Many alkanes are 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
Alkanes
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”
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
is a prefix for the # of carbons Table 7-3,
page 244
IUPAC Names
Name
# carbons Structural Formula
Methane
1
CH4
Ethane
2
CH3CH3
Propane
3
CH3CH2CH3
Butane
4
CH3CH2CH2CH3
Pentane
5
CH3CH2CH2CH2CH3
Name # carbons
Structural Formula
Hexane 6
CH3CH2CH2CH2CH2CH3
Heptane 7
CH3CH2CH2CH2CH2CH2CH3
Octane
CH3CH2CH2CH2CH2CH2CH2CH3
8
Nonane 9 CH3CH2CH2CH2CH2CH2CH2CH2CH3
Decane 10
CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3
Straight-Chain Alkanes
 Homologous series- a group of
compounds that have a constant
increment of change
 In alkanes, it is: -CH2-
Learning Check
A. What is the condensed formula for
H H H H
H
C
C
C
C
H
H
H H
H
B. What is its molecular formula?
C. What is its name?
Solution
A.
CH3CH2CH2CH3
B.
C4H10
C.
butane