ESTERIFICATION

how is ester formed

alcohol + carboxylic acids

name of process to make ester

'fischer esterification'. alcohol + carboxylic acid *acid catalyst *heat. forms ester + water.

what happens during esterification

OH of carboxylic acid replaced by OCH3 to form new C O bond

isoamyl alcohol + glacial acetic acid =>

isoamyl acetate

ethanol + glacial acetic acid =>

ethyl acetate

methanol + salicylic acid =>

methyl salicylate

ethanol + salicylic acid =>

ethyl salicylate

describe color changes of phenolphtalein before and during heating

before heating:

• phenolphtalein pink because NaOH in excess (solution is basic)

during heating:

• hydrolysis of ester (saponification) produces carboxylate salt and alcohol

• if enough ester is present, NaOH is consumed and saponification allows ester to fully hydrolyze

• ester + NaOH -(heat)-> carboxylate salt + alcohol

describe color changes of phenolphtalein after heating

• solution becomes less basic

• drops from 8.2 = transition range of phenolphtalein

• if reaction complete and no more excess NaOH, it should be colorless

ester describe

1. carbonyl group with alkoxy group attached to carbonyl carbon

2. volatile

3. lower bp than alcohol and carboxylic acid

structures of carboxylic acids used

structures of alcohols used