3.3.9 Carboxylic acids and derivatives

Question 1

Carboxylic acid function group and what it can be broken into

Answer 1

Carboxyl - COOH
carbonyl - C=O
hydroxyl - OH

Question 2

Are carboxylic acids weak or strong

Answer 2

Weak

Question 3

Carboxylic acids are weak acids whag does this mean

Answer 3

They partially dissociate to form a H+ ion and a carboxylate ion

Question 4

Carboxylate ion
and give ezamples

Answer 4

O
||
R - C
\
O-

            O
            || H7C3 ---- C
              \
              O- butanoate ion

Question 5

Where does equibrum lie when Carboxylic acid disassociates

Answer 5

Lies to
The left as it dissociates poorly

Question 6

Carboxylic acid + metal carbonate -> …

Answer 6

Salt + CO2 + water

Question 7

carboxylic acid + metal s
eg methanoic acid + sodium

Answer 7

salt + hydrogen gas
sodium methanoate and h2

Question 8

carboxylic acids react with metal oxides and hydroxides to form

Answer 8

salt + water

Question 9

How to form esters (2 ways)

Answer 9

• Reacting Alcohol + Carboxylic acid and sulfuric acid catalyst
• alcohol + acid anhydrid

Question 10

Ester functional group

Answer 10

O
||
C
\
O

Question 11

ester general fomula

Answer 11

R1COOR2
R2 starts w a carbon atom

Question 12

Equation for reacting Carboxylic acid with alcohol and cond

Answer 12

Carboxylic acid + alcohol -> ester + water
- strong acid catalyst like hcl or h2so4
- heat

Question 13

Acid anhydride and alcohol equation

Answer 13

Acid anhydride + alcohol -> ester + Carboxylic acid

Question 14

2 part process in naming esters

Answer 14

1) name alkyl group eg ethyl methyl
2) name part of ester formed from Carboxylic acid instead of using -oic acid we use - oate
Eg propanoate

Question 15

4 Uses of esters and explain the property of esters that gives them thus ability

Answer 15

Eg fragrances
and food flavouring cus they’re sweet smelling,soluble in ethanol,volatile,dont react w h2o and non toxic
- solvents bc they’re polarso will dissolve readily in other polar compounds
- plasticisers - make plastics more flexible during polymerisation process they can leach out of the plastic over time

Question 16

2 methods of ester hydrolysis

Answer 16

Acid hydrolysis
Base hydrolysis

Question 17

Describe method of acid hydrolysis

Answer 17

Dilute hydrochloric acid
heat Under reflux splitting up ester into alcohol and Carboxylic acid
reaction is reversible

Question 18

Describe method of base hydrolysis
saponification

Answer 18

Base - excess dilute NaOH heat under reflux spitting up ester into carboxylate salt and an alcohol
reaction not reversible

Question 19

when we react glycerol and fatty acids we produce…

Answer 19

an ester which makes fats and oils

Question 20

glycerol IUPAC name

Answer 20

propan - 1,2,3 - triol

Question 21

2 kinds of fatty acid and explain them

Answer 21

saturated - single c-c bonds
unsaturated - double c=c bonds

Question 22

unsaturated fatty acids with more double bonds are called…

Answer 22

polyunsaturated fatty acids

Question 23

an oil and fats are an example of an …

Answer 23

ester

Question 24

ester link

Answer 24

O
ll
O - C

Question 25

what kind of hydrocarbon chains does vegetable oil have and what does this mean

Answer 25

*unsaturated* hydrocarbon chains so theyre *not straight* and *cannot pack closely together* due to *lower vdw* forces lower mp and *liquids @ room temp*

Question 26

what kind of hydrocarbon chains do animal fats have and what does this mean

Answer 26

saturated hydrocarbon chains staight and more unifrom higher vdw solid at room temp

Question 27

animal fats and vegetable oils can be hydrolysed by heating them with _____ ______ the product is ______

Answer 27

animal fats and vegetable oils can be *hydrolysed* by heating them with *sodium hydroxide* the product is *soap*

Question 28

what can vegetable oils be converted into and how

Answer 28

biodiesel by reacting oils w methanol and *potassium hydroxide catalyst*

Question 29

oil plus methanol makes ...

Answer 29

makes gylcerol and methyl ester in presense of KOH catalsyt

Question 30

why is thanol suitable solvent for heating cocunut oil w koh give saftey prec and justificartion

Answer 30

dissolves both oil and koh use water bath to heat prevemt fire/ ethanol is flammable

Question 31

biodisel is a mixture of

Answer 31

methyl ester of long chain carboxylic acids

Question 32

biodisel is produced by

Answer 32

reacting vegetable oils with methanol in the presense of strong alkali catalyst

Question 33

acyl chloride functional group

Answer 33

O // C \ Cl

Question 34

acyl chloride general formula

Answer 34

RCOCl

Question 35

ethanoyl chloride + water --> ...

Answer 35

ethanooic acid + HCl

Question 36

structure of biodiesel

Answer 36

https://www.physicsandmathstutor.com/pdf-pages/?pdf=https%3A%2F%2Fpmt.physicsandmathstutor.com%2Fdownload%2FChemistry%2FA-level%2FTopic-Qs%2FAQA%2FOrganic-II%2F3.09-Carboxylic-Acids-and-Derivatives%2FSet-I%2FCarboxylic%20Acids%20and%20Derivatives%20MS.pdf

Question 37

explain how co2 causes global warming (2)

Answer 37

C=O Bonds in CO2 absorb infrared radiation IR radiation emitted by the earth does not escape (from the atmosphere)

Question 38

A compound has reacted w water and produced a carboxylic acid and hcl gas white steamy fumes Is it a acyl chloride or acid anhydride

Answer 38

Acyl chloride as when they react with water they produce hcl white steamy fumes

Question 39

outline the method used for recrystallisation (5)

Answer 39

Dissolve the product in the minimum volume of hot solvent Allow the solution to cool and allow crystals to form. Filter off the pure product under reduced pressure / using a Buchner funnel and side arm flask

Question 40

Test for carboxylic acid

Answer 40

React w carbonate - will produce co2 so effervescence or fizzing