Alcohols

Butanol, that's an alcohol, right.  So it must be safe to drink?

WRONG.

Butanol is used as a fuel.  If you are a human(hopefully), you wouldn't want to injest any of that...



Although we use the term alcohol to refer to the beverages we drink, the only one we actually drink is ethanol.  There are many other alcohols like methanol, propanol, and glycerin.  Alcohols are often used in the pharmacutical industry, to isolate compounds and to obtain dynamite.  Many are poisonous, and can kill you.  For example, propanol(rubbing alcohol) is often used in hand sanitizers. 



While this may look innocent to you, used incorrectly, may cause you death.  Just propanol can cause central nervous system poisoning or a coma.  You die if your respiratory system no longer functions.   

Click the link below to hear a funny song about ethanol.
St. Patrick Day Song- Alcohol



So what makes an alcohol an alcohol?

Alcohols are all colourless, odourless liquids.  They have high boiling points because of the strong attraction between the hydrogen and the carbon atoms. The longer the Carbon chain, the less soluable the molecule is.

Alcohols all have the funtional group "OH" attatched to their structure.

This is the general model:

In this diagram, the 'R' represents a Carbon chain. 

Although they have 'OH' in their structure, they are NOT necessarily basic. 

Naming Rules:

1) Identify the longest carbon chain with the group 'OH'.

2) Assign each Carbon a number.  Give the lowest to that bonded to the 'OH'.

3) Count the number of Carbons.  This will be your parent chain so name the chain as if it were an alkane.

4) Take the 'ane' off the end and add the suffix 'ol'.

5) Name the other substituents and add them to the name at the beginning.  Arrange them in alphabetical order.  

Let's do an example.    

If each intersection represents a Carbon atom, there are five.  Without the 'OH', this would be a pentane molecule.  Take off 'ane' from the ending and replace it with 'an'(because it's still an alkane) and add 'ol'.  Simple.  Thats it. The molecule is pentanol. 



Now for a harder one. 

HO-CH

The longest Carbon chain consists of two Carbons.  Therefore, without the 'OH's it would be called ethane. Since there is more than one group of 'OH', we need to identify this in the name.  We use the prefixes di, tri, tetra, penta, etc. to convey this information.  We put this in front of the suffix 'OL'.  So, ethandiol.  As well, the 'OH' groups are not both bonded to the first Carbon, so we need to dictate their locations. 
The final name of this molecule is 1,2-ethandiol.

2-CH2-OH