Tetrahedral carbon compounds
In saturated organic compounds, all of the carbon atoms are tetrahedral.
- A chloroalkane is an alkane in which one or more hydrogen atoms are replaced with chlorine atoms.
- Chloroform (
- ) is an example of a chloroalkane.
- Chloroalkane’s main uses:
- For removing oil and grease marks from machinery and in dry cleaning of clothes.
- Paint stripper.
- Correcting fluid, e.g. Tippex.
- The alcohols form a homologous series of organic compounds, of general formula
- The -OH group is called the hydroxyl group and is the functional group of alcohols.
- A functional group is an atom or group of atoms which are responsible for the characteristic properties of a series of organic compounds.
- Alcohols may be classified as primary, secondary or territory alcohols.
- A primary alcohol is one where the carbon atom joined to the -OH group is attached to only one other carbon atom. e.g. ethanol.
- In a secondary alcohol, the carbon atom joined to the -OH group is attached to two other carbon atoms. e.g propan-2-ol.
- In a tertiary alcohol, the carbon atom joined to the -OH group is attached to three other carbon atoms, e.g. 2-methylpropan-2-ol.
- The best known alcohol is ethanol. Ethanol is found in alcoholic drinks.
- Ethanol for alcoholic drinks is made by fermentation of sugars in fruits which contain sugar glucose. e.g. grapes.
- In fermentation, enzymes in yeast break down the sugar to give carbon dioxide and ethanol.
- Ethanol is also used was a fuel and as a solvent. e.g. paints, perfumes, after-shaves, etc.
Planar carbon compounds
Planar compounds have a carbon-carbon or carbon-oxygen double bonds. The atoms in the double bonds are planar.
- Aldehydes form a homologous series of organic compounds containing the -CHO functional group. Its general formula is
- All aldehydes contain the carbonyl group.
- They are named by replacing the -e at the end of the corresponding alkane name with -al.
- Dipole-dipole attractions exist between adjacent aldehyde molecules of a carbon-oxygen double bond ( C = O ).
- This leads to increase in boiling points when compared with similar relative molecular mass but lower than those comparable alcohols.
- The only aromatic aldehyde on our course is benzaldehyde. It is found in the oil of almonds.
- The functional group of the ketones is >C=O.
- Ketones are named by replacing the -e at the end of the corresponding alkane name with -one.
- The physical properties of ketones are very similar to those of aldehydes, but the lower ketones are liquids at room temperature and are soluble in water.
- Uses: propanone is used as solvent. e.g. for nail varnish remover.
- Carboxylic acids are a family of organic compounds that contain the carboxyl functional group, -COOH. Its general formula is
- Carboxylic acids are named by replacing the -e at the end of the corresponding alkane name with -oic acid.
- Methanoic acid is found in the stings of nettles and ants.
- Ethanoic acid is used to make a chemical called cellulose acetate, which is used in varnishes, lacquers, photographic film for camera and a type of textile called reyon.
- Propanoic acid, benzoic acid are used as food preservatives.
- Esters are a family of compounds of general formula RCOOR’. The functional group is the -COO- group.
- They have low boiling points.
- They have strong and pleasant smells.
- Fats and oils are long chain carboxylic acids which are naturally occurring esters.
- Uses: Ethyl ethanoate is used as a solvent for printing inks and paints.