Hydrocarbon Essay

Experiment #3 - Hydrocarbons
Introduction
Organic chemistry is the chemistry of the compounds of carbon. Currently over twenty million compounds have been reported in the chemical literature; about 90% of them are organic, ie they contain carbon. The remaining compounds are called inorganic and are formed from the other elements, of which there are about 100. That carbon so dominates compound formation is a result of the fact that it is almost unique in its ability to form long chains with other carbon atoms. [Carbon’s neighbor in the periodic table, silicon, can do this but rarely does.] These chains with one carbon joined to a second and the second joined to a third, etc., can be branched, ie, chains of carbon atoms can be attached to carbons in the original chain. It is also possible for one carbon in a chain to become bonded to another carbon in that chain, resulting in a closed ring of atoms. We call these compounds cyclic. H

H HH HH H
H
HC
C
C
C
C
C
C
CH
H
H HH HH H
H
octane - unbranched (straight-chain)
H

H HH HH H
H
HC
C
C
C
C
C
C
CH
H
H CH CH H
H
H H H HH C H
HH
4-ethyl-2-methyloctane - branched
HHH
C CHH H
H
C
CCCH
H
CC
HH
H
H
HH
H

Since there are so many organic compounds it is fortunate that we can organize them into various groups that have some ethylcyclohexane - cyclic similarity to each other. For example, one large group of organic compounds is known as the
Figure 1 - Unbranched, branched, and hydrocarbons because members of this group cyclic hydrocarbons. contain only carbon and hydrogen and no other elements. Figure 1 shows examples of branched, unbranched and cyclic hydrocarbons.
It is possible to subdivide the hydrocarbon group of compounds based on the bonding between the carbons. If all the carbon-carbon bonds are single, the compound is an alkane. If at