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.