Alcohols

Alcohols are identified as having an -OH (hydroxyl) functional group attached to the parent chain. This (relatively) strong intermolecular force increases alcohol melting and boiling points. Because of the -OH atoms, alcohols are polar. However as the carbon chain (non-polar) increases in length, the overall polarity will become less polar. 

Alcohols can be made from haloalkanes and from oxidation of alkenes. Alcohols can undergo substitution, elimination, and oxidation reactions. For substitution reactions PCl₃ or SOCl₂ are sources of Cl, which replaces the -OH group. Elimination of alcohols to form alkenes is also a 'dehydration' reaction (concentrated H₂SO₄ reagent). ONLY primary alcohols oxidise to form carboxylic acids. Oxidants such as potassium permanganate (KMnO₄) and potassium dichromate (K₂Cr₂O₇) are reagents for this reaction. Potassium permanganate is purple and turns colourless when it reacts. Potassium dichromate is orange and turns green.