Carboxylic Acids

The functional group of carboxylic acids is the carboxyl group - general form: R - COOH O O C R H O carbonyl group hydroxyl group

 Organic acids common in both plants and animals.  Sour taste in fruits (citric acid), vinegar (acetic acid).  Amino acids are carboxylic acids.  Fats (fatty acids) contain large carboxylic acids.

Polar covalent - soluble in water - Larger not soluble IMF of polar bond gives high boiling / melting points. O O C R H O H + O O C R O _ Carboxylic acids are weak acids that ionize when dissolved.

 Name parent chain containing carboxyl group.  Replacing the –e ending with –oic acid.  Numbering always begins with the carbon containing the carboxyl group. NAMING Carboxylic Acids methanoic acid formic acid

butanoic acid CH 3 -CH 2 -CH 2 -C O \ OH // CH 3 COOH CH 3 -C OH O // \ ethanoic acid acetic acid (vinegar) benzoic acid

CH 3 -CH 2 -CH 2 -CH-C O \ OH // CH 3 \ 4-methylpentanoic acid CH 3 CH(CH 3 )CH 2 CH 2 COOH

 Functional group - carboxyl R – COOH  Name parent chain, drop –e, add –oic acid.  Polar molecules - high melting / boiling points.  The smaller acids are soluble in water.  In water - dissociate and release hydrogen ions.