Caboxlyic Acids And Esters✅

Question 1

Why are carboxylic acids soluble

Answer 1

Partial negative charges and lone pair of electrons on O atoms. And positive charges on H means it forms hydrogen bonds with water, the longer the carboxylic acid the less soluble it is

Question 2

Why are carboxylic acids weak acids

Answer 2

Will partially dissociate H from hydroxyl group making them weak acids

Question 3

What is a carboxylate ion

Answer 3

Is the conjugate base of a carboxylic acid; in carboxylate salts and then H of the -OH group has been replaced by a metal

Question 4

When a carboxylic acid reacts with an alcohol in presence of an acid catalyst what is formed

Give eg with Ethanoic acid and ethanol

Answer 4

Ester and water formed

Ethanoic acid+ ethanol——>ethylethanoate + H20. H+

Question 5

What does the name of an ester derive from give eg with methylpropanonate

Answer 5

Methyl-is derived from alcohol methanol

Prop- signifies 3 Carbons present in carboxylic acid parent molecule

Anonate- is suffix for esters

Question 6

Why do acyl compounds take part in nucleophilic addition-elimination reactions

Answer 6

Acyl group R-C=, difference in electronegativity of elements with these functional groups may lead to polarity within compounds

Question 7

How are acyl compounds formed

Answer 7

Prepared from carboxylic acids using SOCl2

Question 8

What does acyl chlorides and acid anhydrides react with alcohols to form

Answer 8

Form esters (nucleophilic addition-elimination reaction)

Including phenol with does not form an ester with carboxylic acids

Question 9

Explain mechanism of how CH3COCl+ C2H5OH——> CH2COOC2H5 + HCl

Answer 9

The lone pair of electrons on O of C2H5OH attracted to slightly positive C of C=O(Cl)

This forms a C-O with CL and C-O attached to C2H5, the bond between C-Cl goes to Cl and lone pair on O goes to bond between C-O

H bond goes to O

Question 10

Esters can undergo hydrolysis in either acidic or alkaline conditions, what do they form

Answer 10

Acid conditions: form carboxylic acids and alcohols

Bases: form salts of carboxylic acids

Question 11

Acyl chlorides snd acid anhydrides react with water in nucleophilic addition-elimination reactions what do they form
Finish equation: CH2COCl+H20—->

Answer 11

Carboxylic acid

CH3COOH+HCl

Question 12

Acyl chlorides and acid anhydrides react with ammonia in nucleophilic addition-elimination, what do they form

Finish equation: CH3COCl+2NH3

Answer 12

Form amides
—>CH3CONH2+HCl

Question 13

Acyl chlorides and acid anhydrides react with primary amines in nucleophilic addition-elimination reactions, what does it form

Finish equation: CH3COCL+CH3NH2

Answer 13

An N-substituted amide

——>CH3CONHCH3