|
| |
Simple Alkanes
The simplest alkanes have two-part names. (More complex molecules will have
additional parts as needed.) The first part of the name for a simple alkane tells how
many carbon atoms are in the molecules. The second part is simply -ane
to indicate single bonds only.
| Ten of these alkanes are listed here. I would like you to learn these ten
names and be able to associate each of those names with the molecular formula shown next
to it, specifically the number of carbon atoms shown in the formula. You
can memorize the number of hydrogen atoms if you want, but you can figure them out very
easily when you need to, as you will see. |
| Name |
Molecular
Formula |
| methane |
CH4 |
| ethane |
C2H6 |
| propane |
C3H8 |
| butane |
C4H10 |
| pentane |
C5H12 |
| hexane |
C6H14 |
| heptane |
C7H16 |
| octane |
C8H18 |
| nonane |
C9H20 |
| decane |
C10H22 |
|
| You should notice that most of these names contain standard prefixes for numbers: pent
for five, hex representing six, hept representing seven, oct
representing eight, non for nine, and dec for ten. You are probably already
familiar with most of those from the names of various geometric shapes like pentagons and
hexagons. Although meth-, eth-, prop- and but- don't come from the same source, you will
need to become familiar with those prefixes meaning one, two, three and four carbon atoms
respectively. |
| pent- |
5 |
| hex- |
6 |
| hept- |
7 |
| oct- |
8 |
| non- |
9 |
| dec- |
10 |
|
To review, the names of these alkanes are made up of two parts. The first part
represents the number of carbons (that would be the meth-, eth-,
prop-, but-, pent-, hex-,
hept-, oct-, non-, and dec-);
and the second part is -ane. These prefixes form the basis for the names
of most of the compounds that we will be naming during this course. Keep in mind that all
ten of these compounds have C and H single bonds only.
Practice
| Try naming the compounds shown here (they are also in exercise 9 of your
workbook), before continuing. The answers are shown below. |
CH3CH3
CH3CH2CH2CH2CH3
CH3(CH2)6CH3 |
|
Answers
CH3CH3 |
ethane |
CH3CH2CH2CH2CH3 |
pentane |
| CH3(CH2)6CH3 |
octane |
Top of Page
E-mail instructor:
Eden Francis
Clackamas Community College
©2001, 2003 Clackamas Community College, Hal Bender
|
