2.1: Carboxylic Acids - Structures and Nomenclature Simple carboxylic acids are best known by common names based on Latin and Greek words that describe their source (e.g., formic acid, Latin formica, meaning “ant”). Greek letters, not numbers, designate the position of substituted acids in the common naming convention. IUPAC names are derived from the LCC of the parent hydrocarbon with the -e ending of the parent alkane replaced by the suffix -oic and the word acid. 2.2: Physical Properties of Carboxylic Acids Carboxylic acids have high boiling points compared to other substances of comparable molar mass. Boiling points increase with molar mass. Carboxylic acids having one to four carbon atoms are completely miscible with water. Solubility decreases with molar mass. 2.3: Chemical Properties of Carboxylic Acids I- Acidity and Salt formation Soluble carboxylic acids are weak acids in aqueous solutions. Carboxylic acids neutralize bases to form salts. 2.4: Chemical Properties of Carboxylic Acids II- Formation of Esters 2.5: Nomenclature of Esters An ester has an OR group attached to the carbon atom of a carbonyl group. 2.6: Physical Properties of Esters Esters have polar bonds but do not engage in hydrogen bonding and are therefore intermediate in boiling points between the nonpolar alkanes and the alcohols, which engage in hydrogen bonding. Ester molecules can engage in hydrogen bonding with water, so esters of low molar mass are therefore somewhat soluble in water. 2.7: Synthesis of Esters Esters are made by the reaction of a carboxylic acid with an alcohol, a process that is called esterification. 2.8: Acid Halides for Ester Synthesis Acyl halides (acid halides) are synthsized from carboxylic acids. Acyl chlorides are more reactive than carboxylic acids. 2.9: Acid Anhydrides for Ester Synthesis Acid anhydrides are typically synthesized from acyl halides. Acid anhydrides undergo hydrolysis and nucleophilic acyl substitution reactions. 2.10: Reactions of Esters Hydrolysis is a most important reaction of esters. Acidic hydrolysis of an ester gives a carboxylic acid and an alcohol. Basic hydrolysis of an ester gives a carboxylate salt and an alcohol. 2.11: Esters of Phosphoric Acid Inorganic acids such as \(H_3PO_4\) form esters. The esters of phosphoric acid are especially important in biochemistry. 2.12: Thioesters- Biological Carboxylic Acid Derivatives Thioesters are biologically important carboxylic acid derivatives. Acetyl coenzyme A is an important thioester in metabolism and transports two carbon atoms to the Citric Acid Cycle (Kreb's Cycle). 2.13: Polyesters This page looks at the formation, structure and uses of a common polyester sometimes known as Terylene if it is used as a fibre, or PET if it used in, for example, plastic drinks bottles