Question

Name :
(a) compound formed when acetic acid and ethanol react together.
(b) the reducing agent used to convert acetic acid into ethanol.
(c) the substance used to change acetic acid to acetic anhydride.

Answer 1

(a) Alcohols react with carboxylic acids in presence of conc. sulphuric acid to form esters.

$C{H}_3-COOH+C{H}_3-C{H}_{2}OH\stackrel{Conc.H_{2}S{O}_4}{\to }C{H}_3-COO-C_2{H}_5+H_{2}O$

(b) Lithium Aluminum Hydride is a very strong reducing agent which will reduce most carbonyls to an alcohol. Sodium borohydride is a good reducing agent. Although not as powerful as lithium aluminium hydride $\left(LiAl{H}_4\right)$, it is very effective for the reduction of aldehydes and ketones to alcohols.

$\underset{Ethanoicacid}{C{H}_{3}COOH}\underset{H_{2}O}{\overset{LiAl{H}_4}{\to }}\underset{Ethanol}{C{H}_{3}C{H}_{2}OH}$

(c) It hydrolyzes in water to yield acetic acid. ... Acetic anhydride can be prepared by the dehydration of acetic acid at 800°C.

$OOO||||||\underset{Ethanoicacid}{C{H}_{3}C-OH}\underset{-H_{2}O}{\overset{{800}^{\circ }C}{\to }}\underset{Acidanhydride}{C{H}_3-C-O-C-C{H}_3}$

Alternatively, the reaction between the acid chloride and a salt of the acetic acid (e.g. sodium acetate) yields acetic anhydride and a salt

$OOOO||||||||\underset{AcidChloride}{C{H}_{3}C-Cl}+\underset{Sodiumacetate}{Na-O-C-C{H}_3}⟶\underset{Acidanhydride}{C{H}_3-C-O-C-C{H}_3}+NaCl$