Carboxylic Acids And Esters

Question 1

When naming esters the first part of the name comes from….. and the second part comes from…..

Answer 1

…..alcohol
…..carboxylic acids

Question 2

Esters are formed from….

Answer 2

Carboxylic acids and alcohols

Question 3

What is always the by product when forming Esters

Answer 3

Water

Question 4

What catalyst is used to form ester from carboxylic acid and alcohol

Answer 4

Conc H2SO4

Question 5

Hydrolysis of esters is when

Answer 5

Esters are hydrolysed back to their constituent carboxylic acids and alcohol using water

Question 6

What are the two types of hydrolysis

Answer 6

Acid catalysed hydrolysis and base catalysed hydrolysis

Question 7

What is the reactants and products of an acid catalysed hydrolysis

Answer 7

Ester + H2O ==(conc H2SO4)==> carboxylic acid + alcohol

Question 8

Base catalysed hydrolysis uses what catalyst

Answer 8

Warm aqueous NaOH

Question 9

What is the equation for a base catalysed hydrolysis

Answer 9

Ester + H2O ==(NaOH)==> salt (sodium…..) + alcohol

Question 10

What is the equation for acid hydrolysis

Answer 10

Triester + 3H2O ==(reflux conc acid catalyst)==> propane-1,2,3-triol + 3 x ester

Question 11

Base hydrolysis equation

Answer 11

Triester + 3NaOH ==(reflux)= => propane-1,2,3-triol + soap (carboxylic acid salts)

Question 12

What is biodiesel

Answer 12

A mixture of methyl esters

Question 13

What is biodiesel used for

Answer 13

-To conserve crude oil supplies
-reduce the amount of co2 released

Question 14

Uses of esters are

Answer 14

• solvents
  -plasticisers
  -perfumes
  -flavourings

Question 15

Equation for biodiesel

Answer 15

Tri-ester + 3CH3OH ==(NaOH) ==> propane-1,2,3-triol + 3x methyl ester

Question 16

All acyl chlorides have a name ending in….

Answer 16

… ‘oyl chloride’

Question 17

Dehydration of carboxylic acids become…

Answer 17

…acid anhydrides

Question 18

Nomenclature of an acid anhydride

Answer 18

……..oic anhydride

Question 19

Acyl chloride + water makes…

Answer 19

Carboxylic acid

Question 20

Acyl chloride + alcohol makes….

Answer 20

Ester

Question 21

Acyl chloride + ammonia makes

Answer 21

Amide

Question 22

Acyl chloride + amine (ethylamine)

Answer 22

N- substituted amide

Question 23

What is the mechanism called for acyl chloride + water/alcohol/ammonia/amines

Answer 23

Nucleophilic addition-elimination

Question 24

Naming amines

Answer 24

…….amine or amino ‘alkane’

Question 25

Naming amides

Answer 25

…anamide

Question 26

By product is HCL for which reactions

Answer 26

Acyl chloride and water/alcohol/ammonia/amine

Question 27

What else is formed in when acyl chloride and ammonia react

Answer 27

Ammonium chloride
NH4Cl

Question 28

How do we know HCl is produced

Answer 28

White misty fumes

Question 29

What else is produced when acyl chloride and amine react

Answer 29

Ammonium chloride salt

Question 30

Nucleophilic addition elimination mechanism key points

Answer 30

• arrow from c=o onto O
  -arrow from nucleophile to c+
• draw it out again with nucleophile attached
• O reforms C=O bond
• C-Cl bond breaks
  -arrow from nucleophile and H goes to the nucleophile

Question 31

Why are acid anhydrides more commonly used over acyl chlorides

Answer 31

• they are cheaper
  -less corrosive
  -don’t react with water
  -safer as side product is carboxylic acid whereas acyl chloride produces HCl