In this introduction to organic chemistry you will learn:
- The definition of a hydrocarbon and - How functional groups give molecules similar
properties Organic chemistry is the study of carbon compounds.
There are many millions of organic compounds that you can make using hydrogen and carbon
and arranging them in different ways.
Hydrocarbons are defined as compounds made of hydrogen and carbon only.
The simplest hydrocarbon is methane it consists of one carbon with four covalent bonds to
hydrogen atoms.
The next in the series has two carbon atoms and this is called ethane and is followed
by propane and butane these being the names of the first four in the series called the
alkanes.
Pause this video now and try to draw the structure of hexane.
Hexane has 6 carbon atoms.
(PAUSE) The next series is called the ALKENES.
These are hydrocarbons that contain a double covalent bond between two carbon atoms in
the molecule.
Our first alkene molecule contains two carbons atoms.
Just like the alkanes, each carbon atom still needs 4 bonds, but has two bonds already due
to the double covalent bond with the other Carbon atoms.
The ethane molecule is completed by two more bonds with two Hydrogen atoms, for each of
the Carbon atoms.
These also follow a pattern and the next molecule in the series is propene and butene.
Pause this video now and try to draw the structure of hexene.
As before, hexane still has 6 carbon atoms.
(PAUSE) The video tutorial on the alkanes and alkenes
will give you more in-depth knowledge on the bonding and structure of these series of molecules.
As we have already discussed, hydrocarbons are molecules containing only carbon and hydrogen
atoms, however, the study of organic chemistry includes any molecule with a carbon backbone.
Functional groups are groups of atoms which give molecules similar properties.
There are many different functional groups.
You may have heard of the alcohol group.
This is a hydroxyl group and is a hydrogen bonded to an oxygen which is then covalently
bonded to the rest of the molecule.
This group can be attached to any of the alkanes above to form alcohols their names all end
in -ol.
For example: - Methanol
- Ethanol - Propanol
Pause this video now and try and work out the name of this molecule?
(PAUSE) The alcohol functional group means that all
these compounds will react in a similar way and will have similar properties.
Carboxylic acids are another example of a functional group.
This is the functional group for a carboxyl acid and gives an organic molecule the name
-oic acid.
For example: - Methanoic acid
- Ethanoic acid, - Propanoic acid
- Butanoic acid There are lots more functional groups, esters
which give molecules a sweat smell and makes them useful for perfumes and flavourings.
Ketones, which make molecules useful as solvents.
Amines which can be useful as dyes and useful in making medicines.
Some molecules even have more than one functional group and give molecules different properties.
Now, by the end of this video, you should know that organic chemistry is the study of
carbon based molecules and that hydrocarbons are molecules containing hydrogen and carbon
only.
You should know that functional groups are groups of atoms which give molecules similar
properties.