Esters of glycerol and long chain carboxylic acids (fatty acids)
1 of 55
What can vegetable oils and animal fats can be hydrolysed to give?
Soap, glycerol and long chain carboxylic (fatty) acids
2 of 55
What does glycerol do?
Form hydrogen bonds very easily and is readily soluble in water
3 of 55
What is it used in?
Cosmetics, food and glues
4 of 55
What is soap?
Long chain carboxylic fatty acids produced by the hydrolysis of fats, acts as soaps
5 of 55
What is the polar CO2^-1 end?
Hydrophilic and mixes with water
6 of 55
What is the long non-polar hydrocarbon chain?
Hydrophobic and mixes with grease so allows the grease and water to mix and be washed away
7 of 55
What is biodiesel?
Mixture of methyl esters of long chain carboxylic acids
8 of 55
What can vegetable oils be converted into? how?
Biodiesel by a reaction with methanol in the presence of a strong alkali catalyst
9 of 55
What are two carboxylic acid derivatives?
Acyl chlorides and acid anhydrides
10 of 55
What are acyl chlorides
similar to carboxylic acid but OH replaced by Cl
11 of 55
What are acid anhydrides?
2 carboxylic acids joined by oxygen with no OH groups
12 of 55
What are acyl chlorides?
Much more reactive than carboxylic acids
13 of 55
What are the Cl and -OCOCH3 groups classed as?
Good leaving groups (less effective delocalisation ) making acyl chlorides and acid anhydrides much more reactive than carboxylic acids and esters
14 of 55
What do acid anhydrides have similar reactivity to?
Acyl chlorides and therefore can bring about the same change in functional group
15 of 55
What is the main difference?
By-products. Acyl chlorides mostly give off HCL whereas acid anhydrides give off RCOOH
16 of 55
Acyl chloride + water
carboxylic acid
17 of 55
Reagent
Water
18 of 55
Conditions
Room temp
19 of 55
eqn
RCOCl(l) + H2O = RCO2H
20 of 55
Observation
Steamy white fumes of HCl are given off
21 of 55
Acid anhydride plus water
Carboxylic acid
22 of 55
Reagent
water
23 of 55
Conditions
room temp
24 of 55
EQN
(RCO)2O + H2O = 2RCO2H
25 of 55
Steps nucleophilic addition elimination reaction
Lone pair on oxygen attack slightly positive carbon, electrons move from double bond to oxygen, electrons reform double bond then Cl eliminated along with H from water cause O has 3 bonds
26 of 55
Acyl chloride + Alcohol
Ester
27 of 55
Reagent
Alcohol
28 of 55
conditions
Room temp
29 of 55
eqn
RCOCl + CH3CH2OH = RCO2CH2CH3 + HCl
30 of 55
Observation
Steamy white fumes of HCl are given off
31 of 55
Wy is this reaction for making esters better than using carboxylic acids?
Rxn quicker and its not reversible
32 of 55
Acid anhydride + alcohol =
ester
33 of 55
Reagent
Alcohol
34 of 55
conditions
room temp
35 of 55
ENQ
(RCO)2O+CH3CH2OH= RCO2CH2CH3+ RCO2H
36 of 55
Acyl chloride +ammonia=
Primary amide
37 of 55
reagent
ammonia
38 of 55
conditions
Room temp
39 of 55
RCOCl + 2NH3 =
RCONH2 + NH4Cl
40 of 55
Observation
white smoke of NH4Cl is given off
41 of 55
Acid anhydride + ammonia
Primary amide
42 of 55
Reagent
Ammonia
43 of 55
conditions
room temp
44 of 55
(RCO)2O+2NH3=
RCONH2+ RCO2^-NH4^+
45 of 55
Acyl chloride + primary amine
Secondary amide
46 of 55
Reagent
Primary amine
47 of 55
Conditions
room temp
48 of 55
RCOCl + 2CH3NH2=
RCONHCH3 + CH3NH3+Cl-
49 of 55
Acid anhydride + Primary amine
Secondary amide
50 of 55
Reagent
Primary amine
51 of 55
Condtions
Room temp
52 of 55
EQN
(RCO)2O + 2CH3NH2 = RCONHCH3 + RCO2^-CH3NH3^+
53 of 55
Making asprin
Phenol group turned into ester by reacting with reactive ethanoic anhydride
54 of 55
Why is ethanoic anhydride used instead of acid chlorides?
Cheaper, less corrosive, less vulnerable to hydrolysis and less dangerous to use
55 of 55
Other cards in this set
Card 2
Front
What can vegetable oils and animal fats can be hydrolysed to give?
Back
Soap, glycerol and long chain carboxylic (fatty) acids
Comments
No comments have yet been made