Carbonyls and Carboxylic Acids and their Derivatives

Question 1

Catalyst for formation of esters from alcohol + COOH

Answer 1

Conc acid eg. H2SO4

Question 2

Catalyst for hydrolysis of esters

Answer 2

Dilute strong acid eg. Dilute H2SO4

Question 3

Advantages of base hydrolysis

Answer 3

Reaction goes to completion due to neutralisation by base, more product in the mixture than by acid hydrolysis

Question 4

Uses of glycerol and sodium salts

Answer 4

Soaps and cleaning products

Question 5

Acid + metal —>

Answer 5

Salt + hydrogen

Question 6

Acid + alkali —>

Answer 6

Salt + water

Question 7

Acid + carbonate —>

Answer 7

Salt + water + CO2

Question 8

Uses of esters (4)

Answer 8

Perfumes, flavourings, solvents, plasticisers for polymers

Question 9

Are esters soluble or insoluble in water

Answer 9

Almost insoluble

Question 10

Conditions for acid hydrolysis

Answer 10

Dilute acid, heat under reflux

Question 11

Conditions for base hydrolysis

Answer 11

Dilute NaOH, heat under reflux

Question 12

Products of base hydrolysis

Answer 12

Carboxylate salt + alcohol

Question 13

Why isn’t base hydrolysis reversible

Answer 13

The carboxylate salt is the anion of the COOH, the anion is resistant to attack by weak nucleophiles eg. alcohols so it’s not reversible

Question 14

Uses of glycerol

Answer 14

Soluble in water so good in cosmetics, food and glues

Question 15

How does soap work

Answer 15

The polar CO2 - end is hydrophilic and mixes with water, the long non- polar hydrocarbon chain is hydrophobic and mixes with grease. So grease and water can mix and be washed away

Question 16

Catalyst for vegetable oils + methanol —> biodiesel

Answer 16

Strong alkali catalyst

Question 17

Vegetable oil + methanol —>

Answer 17

Biodiesel

Question 18

Which is more reactive acyl chlorides or COOH

Answer 18

Acyl chlorides

Question 19

Acyl chloride + water —>

Answer 19

COOH + HCl

Question 20

Reagent and conditions for Acyl chloride + water

Answer 20

Water, room temp

Question 21

Acid anhydride + water —>

Answer 21

COOH

Question 22

Reagent and conditions for acid anhydride + water

Answer 22

Water, room temp

Question 23

What type of mechanism is acyl chloride + water

Answer 23

Nucleophilic addition elimination

Question 24

Acyl chloride + alcohol —>

Answer 24

Ester + HCl

Question 25

Reagent and condition for acyl chloride + alcohol

Answer 25

Alcohol, room temp

Question 26

Observation for Acyl chloride + water

Answer 26

Steamy white fumes of HCl

Question 27

Observation for Acyl chloride + alcohol

Answer 27

Steamy white fumes of HCl

Question 28

Acyl chloride + ammonia —>

Answer 28

Amide + HCl

Question 29

Reagent and conditions for Acyl chloride + ammonia

Answer 29

Ammonia, room temp

Question 30

Acyl chloride + amine —>

Answer 30

N-substituted amide + HCl

Question 31

Observation for acyl chloride + ammonia

Answer 31

White smoke of NH4Cl

Question 32

Acid anhydride + alcohol —>

Answer 32

Ester + COOH

Question 33

Reagents and conditions for acid anhydride + alcohol

Answer 33

Room temp, alcohol

Question 34

Acid anhydride + ammonia —>

Answer 34

Amide + COOH

Question 35

Reagent and conditions for Acid anhydride + ammonia

Answer 35

Ammonia, room temp

Question 36

Acid anhydride + primary amine —>

Answer 36

N- substituted amide + COOH

Question 37

Reagent and conditions for acid anhydride + amine

Answer 37

Amine, room temp

Question 38

In the production of aspirin why is the minimum volume of hot solvent used

Answer 38

To obtain a saturated solution and to enable crystallisation on cooling

Question 39

What reasons are there for a loss of yield in the production of aspirin (3)

Answer 39

Crystals lost when filtering/ washing Some product stays in the solution after recrystallisation Other side reactions occur

Question 40

What happens to the MP if impurities are present

Answer 40

The MP will be lower and it will melt over a range of degrees

Question 41

Ethanoic anhydride is chosen over ethanoyl chloride for the production of aspirin, why?

Answer 41

Doesn’t produce toxic HCl Doesn’t have to be anhydrous so cheaper The by product (ethanoic acid) can react further to give more product

Question 42

Why isn’t ethanoic acid used in the production of aspirin

Answer 42

Ethanoyl chloride and ethanoic anhydride are faster and produce higher yields

Question 43

Reagent for the formation of a hydroxynitrile

Answer 43

HCN or a mix of KCN and HCN

Question 44

What type of reaction is the formation of a hydroxynitrile

Answer 44

Nucleophilic addition

Question 45

What reagent is needed to reduce an aldehyde

Answer 45

NaBH4 dissolved in methanol and water

Question 46

What is an aldehyde reduced to

Answer 46

A primary alcohol

Question 47

What are ketones reduced to

Answer 47

Secondary alcohols

Question 48

What are advantages of biodiesels

Answer 48

Renewable Less CO2 Fewer pollutants Non- toxic

Question 49

Advantages of using methyl esters over triglycerides as fuels in car engines

Answer 49

They don’t have glycerol in so it doesn’t make carbon depositions of pistons They’re less viscous More reliable in cold winter

Question 50

What type of reaction reduces aldehydes and ketones to alcohols

Answer 50

Nucleophilic addition