6.1.3 Carboxylic acids and esters

Question 1

What is the general formula for a carboxylic acid?

Answer 1

R-COOH

Question 2

Describe the functional group of a carboxylic acid?

Answer 2

The carboxylic acid functional group consists of a carbonyl group attached to a hydroxyl group on the same carbon atom

Question 3

Why do carboxylic acids have higher boiling points than alcohols of a similar molar mass c

Answer 3

Carboxylic acids can form multiple hydrogen bonds due to it having the hydroxyl and carbonyl groups
These stronger hydrogen bonds requires more energy to break leading to higher boiling points

Question 4

What type of bonding explains the solubility of carboxylic acids?

Answer 4

Hydrogen bonding

Question 5

What happens when carboxylic acids react with metals?

Answer 5

Carboxylic acids react with metals to produce a salt and hydrogen gas

Question 6

How do carboxylic acids react with metal oxides

Answer 6

Carboxylic acids react with metals to produce a salt and water

Question 7

Describe the reaction of carboxylic acids and alkali?

Answer 7

Carboxylic acids react with alkalis to produce salt and water

Question 8

What are the products of the reaction between carboxylic acids and carbonates ?

Answer 8

Carboxylic acids react with carbonates to produce a salt, water and CO2 gas

Question 9

What is esterification?

Answer 9

Reaction between a carboxylic acid and alcohol in the presence of an acid catalyst
produces ester and water

Question 10

What catalyst is commonly used in esterification of carboxylic acids?

Answer 10

Concentrated sulfuric acid

Question 11

What functional group characterises esters?

Answer 11

R-COOR

Question 12

How are esters formed from acid anhydrides and alcohols?

Answer 12

When acid anhydrides react with alcohols without the need for a catalyst

Question 13

What is the product of acid hydrolysis of an ester

Answer 13

Acid hydrolysis of an ester produces a carboxylic acid and an alcohol

Question 14

What are the products of alkaline hydrolysis of an ester?

Answer 14

Alkaline hydrolysis of an ester produces a carboxylate salt and an alcohol

Question 15

How are acyl chlorides formed from carboxylic acids?

Answer 15

Acyl chlorides formed by reacting carboxylic acids and thionyl chloride

Question 16

Why is thionyl chloride commonly used in the synthesis of acyl chlorides?

Answer 16

Thionyl chloride replaces the hydroxyl group in carboxylic acids with a Cl atom forming acyl chlorides and produces gaseous by products

Question 17

What products are formed when acyl chlorides reacts with water?

Answer 17

forms carboxylic acids and releases HCl gas

Question 18

What reaction occurs between acyl chlorides and alcohols?

Answer 18

esterification as esters form

Question 19

Describe acyl chlorides reaction with ammonia?

Answer 19

Acyl chlorides reacts with ammonia to form primary amides

Question 20

What formed when acyl chlorides react with primary amines?

Answer 20

Secondary amides

Question 21

Why are acyl chlorides used to esterify phenol rather than carboxylic acids?

Answer 21

Acyl chlorides are more reactive than carboxylic acids
enabling them to esterify phenol, which doesnt readily react with carboxylic acids

Question 22

What are some uses of carboxylic acids?

Answer 22

food preservation
pharmaceuticals
intermediates in chemical synthesis

Question 23

What is the functional group present in acyl chlorides?

Answer 23

-COCl

Question 24

How can you identify a carboxylic acid in the lab?

Answer 24

Carboxylic acids can be identified by their reaction with carbonates
producing CO2 gas - effervescence caused