Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

organic II > carboxylic acids and esters > Flashcards

carboxylic acids and esters Flashcards

1
Q

why does carboxylic acid dissolve in water and upto what one?

A

It dissolves as it forms hydrogen bonds with water

dissolves up to and including butanoic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what happens if the hydrogen of the cooh is removed?

A

a carboxylate ion is formed
their is a negative charge over the carboxylate ion
this delocalisation makes the resulting ion more stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how are carboxylic acids named?

A

the carbon in the carboxyll group is always the first carbon group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

as carboxylic acids are weak what do they form when reacted with carbonates?

A

salt co2 and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how do you name esters?

A

take the alcohol half as the alkyl group e.g ch3 =methyl

take the carboxylic acid and replace the ending with oate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

descrtibe the uses of esters?

A

fragrance/food-nice smell
solvents- as they are polar they allow polar molecule to dissolve in.they also have a low boiling point
placticisizers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2 reactions for formation of esters

A

alcohol + carboxylic acid ester + h20 (reversible reaction) catalyst of conc sulphuric acid
acid anhydride + alcohol ->ester + carboxylic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the 2 types of ester hydrolysis?

A

acid hydrolysis

base hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe acid hydrolysis of ester?

A

reaction is completed under reflux
acid e,g sulphuric hydrochloric breaks ester down to carboxylic acid + alcohol
ester + h20 ->carboxylic acid + alcohol (acid catalyst)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe base hydrolysis?

A

reaction is completed under reflux
base e.g sodium hydroxide breaks down ester to carboxyate ion + alcohol
ester+ oh- -> carboxylate ion + alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does glyderol (propan-1,2,3triol) and fatty acids (carboxylic acid) combine to make?

A

esters known as oils and fats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

why are oils liquid at room temperature while fats are solid?

A

oils have unsaturated fatty acid chains(double bonds) which are not straight this means they cannot pack as closely together.hence they have weaker van der waals forces and lower boiling points
fats have saturated fatty acid chains which are straight this means they can pack closer together and have stronger wan der waals forces and a higher boiling plint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does the hydrolysis of fats/oils produce soap?

A

in a base hydrolysis usually containing na it combines with carboxylate ion to form a salt which is known as soap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is biodiesel?

A

biodiesel is a mixture of methyl esters and can be made from rapseed oil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the reaction to produces biodiesel from vegetable oil?

A

C3H8O3
oil (ester) + methanol -> glycerol + methyl ester (KOH catalyst)
H 3CH3OH H O
H C O C=O-R H C OH II
H C O C=O-R H C OH 3 H3CO C R
H C O C=O-R H C OH
H H

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the functional group of acyl chlorides and how are they named

A

-COCL
the longest carbon chain with the carbon on the acyl group as 1
adding oyl chloride to the end

17
Q

what are the 4 acyl chloride reactions?and what mechanism do they use ?

A

water + acyl chloride ->carboxylic acid + HCL
alcohol + acyl chloride -> ester + HCL
ammonia + acyl chloride -> primary amide +HCL
primary amines + acyl chloride ->N amide +HCL
nucleophillic addition elimination

18
Q

what is produced when acyl chloride reacts with water?

A

ethanoyl chloride + h20 ->ethanoic acid + hcl

cl oh
c-c=o + h20 -> c-c=o +hcl

19
Q

what is produced when you react acyl chloride with ammonia?

A

ethanoyl chloride + NH3 -> ethanamide + hcl

                                             c-c=o
                                                 nh2
20
Q

what is produced when acyl chlorides react with amines?

A

ethanoly chloride + methyl amine-> N-methylamide + hcl

21
Q

what are acid anhydrides and how are they named?

A

they look like double carboxylic acid
they are named as the carboxylic acid removing the acid and adding anhydride
e.g ethanoic anhydride

22
Q

what is produced when acyl chloride reacts with alcohol?

A

ethanoyl chloride + methanol -> methyl ethanoate + hcl

23
Q

what are the reactions you need to know with acid anhydrides and what is the difference compared to acyl chloride?and what mechanism do they use?

A

acid anhydrides + water-> Carboxylic acid + carboxylic acid
acid anhydrides + alcohol-> ester + carboxylic acid
acid anhydrides + ammonia-> amide +carboxylic acid
acid anhydrides + primary amine -> n substituted amide + carboxylic acid
the difference is they produce carboxylic acid instead of hcl
much less vigourous
nucleophillic addition elimination

24
Q

describe acid anhydride + water

A

acid anhydride + water -> carboxylic acid + carboxylic acid

25
Q

describe reaction of acid anhydride + ammonia?

A

acid anhydride + ammonia -> amide + carboxylic acid

ethanoic anhydride + NH3 -> ethanamide+ ethanoic acid

26
Q

describe reaction of acid anhydride + alcohol?

A

acid anhydride + alcohol->ester + carboxylic acid

ethanoic anhydride + methanol -> methyl ethanoate + ethanoic acid

27
Q

describe reaction of acid anhydride + primary amine

A

acid anhydride + primary amine -> N substitued amide + carboxylic acid
ethanoic anhydride + CH3NH2 -> N methyl ethanamide + ethanoic acid

28
Q

what are the 2 reactions which produce aspirin

A

ethanoic anhydride + salicylic acid => aspirin + ethanoic acid
ethanoyl chloride + salicylic acid -> aspirin + hcl

29
Q

which is the preferred reaction for the production of aspirin and why?

A

ethanoic anhydride + salicylic acid -> aspirin + ethanoic acid

as it is safer less corrosive
does not produce hcl gas which is harmful
does not react vigorously with water

30
Q

describe the reaction for the production of soap from fats?

A

propan123triol
fat (ester) + sodium hydroxide -> glycerol + soap (sodium salt)
CH2OOCC17H31 H C17H31COO-Na+
CHOOCC17H33 +3NaOH -> H C OH C17H33COO-Na+
CH2OOCC17H29 H C OH C17H29COO-Na+
H C OH
H

31
Q

describe the steps of recrystalisation?

A

Add the minimum amount of hot solvent for all the product to dissolve (to ensure its saturated)
allow the products to cool and form crystals
Filter the product using a buchner funnel and side arm flask

32
Q

Explain the purpose of each underlined point.
Minimum volume ………………………………………………………………………………………..
…………………………………………………………………………………………………………………
Hot water ………………………………………………………………………………………………….
…………………………………………………………………………………………………………………
Filtered hot ………………………………………………………………………………………………..
…………………………………………………………………………………………………………………
Cooled in ice ……………………………………………………………………………………………..
…………………………………………………………………………………………………………………
Washed with cold water ………………………………………………………………………………
……………………………………. in re crystalisaton

A

saturated solution to increase yeild
to remove insolouble impurities
maximum yeild
remove impurities

organic II (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions