Ketones, Aldehydes, & Carboxylic Acids!

It was so exciting today in chemistry class because we went over the nomenclature for ketones, aldehydes, and carboxyclic acids!

We learned that a ketone is a hydrocarbon chain with a double bonded oxygen that is NOT on either end. In other words, it is an organic compound containing a C=O group at a position other than at the end of a hydrocarbon chain. The simplest ketone is propanone. As you can see, standard rules apply and we add -ONE to the parent chain.

We also learned that an aldehyde is a compound that has a double-bonded oxygen at the end of a chain. In other words, it is an organic compound containing a CHO group at the end of a hydrocarbon chain. The simplest aldehyde is methanal, which is also called formaldehyde. Again, standard rules apply and we change the parent chain ending to -AL. It's crucial that we don't confuse aldehydes with alcohols and ketones!





 
Finally, we looked at carboxylic acids. It is an organic compound that contains a COOH group. Carboxylic acids use standard rules but change the parent chain ending to -OIC ACID. The simplest carboxylic acid is methanoic acid. They are commonly referred to as "organic acids."



Methanoic acid



EXAMPLES:
KETONES
1.What is the structural formula for 4-octanone?

2.What is the structural formula for 3-hexanone?

3.Name the molecule shown below:

Cyclohexanone



ALDEHYDES
1.What is the structural formula for ethanal?

2.What is the structural formula for 2-methylpentanal?

3.Name the molecule shown below:

Benzaldehyde

CARBOXYLIC ACIDS
1.What is the structural formula for ethanoic acid (commonly called acetic acid)?

2.What is the structural formula for butanoic acid (commonly called butyric acid and is responsible for the odour of "smelly feet")?

3.Name the following carboxylic acid: CH₃(CH₂)₄COOH.



Hexanoic acid


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