Brainscape's Knowledge GenomeTM

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


See full index

Chemistry U6 > Carboxylic acids > Flashcards

Carboxylic acids Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

What is the functional group for carboxylic acid?

A

COOH

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

How are carboxylic acids made?

A

primary alcohols are oxidised into aldehydes

aldehydes are further oxidised into carboxylic acids

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

How are carboxylic acids made?

A

primary alcohols are oxidised into aldehydes

aldehydes are further oxidised into carboxylic acids

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

What is the overall equation for the formation of a carboxylic acid?

A

alcohol + 2[O] > Carboxylic acid + water

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

Which carboxylic acids are very soluble?

A

those with a low molecular mass

this is bc the COOH group forms hydrogen bonding with water

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

Why are carboxylic acids weak?

A

only slightly dissociated in water
only partially give their proton

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

How are carboxylic acids dissociated?

A

carbonyl grouo (C=O) attracts electrons away from the -OH group

this causes the -OH bond to be weakened so it breaks easily to release a proton and produce a carboxylate anion

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

What is the equation for dissociation

A

CH3COOH ⇌ CH3COO- + H+

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

Why are alcohols not acidic?

A

the -OH bond doesn’t break easily

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

Why does the addition of a halogen change a CA acidity?

A
  • halogen is electron withdrawing
  • so OH bond is weaker
  • thus its a stronger acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the test for carboxylic acids?

A

Na2CO3 (sodium carbonate)

observation: effervescence

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

What is the word equation for CA with sodium carbonate?

A

e.g ethanoic acids

ethanoic acid + sodium carbonate > sodium ethanoate + carbon dioxide + water

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

What is the equation for CA and sodium carbonate?

A

e.g methanoic acids ethanoic acid

2COOH + Na2CO3 > 2COO-Na+ + CO2 + H2O

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

How are esters formed?

A

esterification

carboxylic acids react with alcohols in the presence of a strong acids

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

What are the uses of esters

A

flavourings
perfumes
plasticisers

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

What catalyst is used in esterification?

A

Concentrated sulphuric acid (H2SO4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the WORD equation for esterification?

A

carboxylic acid + alcohol ⇌ ester + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the equation for Esterification?

A

e.g methanoic acid

CH3CO OH + CH3O H ⇌ CH3COCH3O + H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you name an ester?

A

the alky chain is the prefix > e.g methanol is methyl etc

the carboxyl-acid is the suffix and changed from -oic to -oate

20
Q

What is a functional group isomer?

A

same molecular formula but different structural formula

21
Q

How can esters be hydrolysed into carboxylic acids?

A

using diluted H2SO4 of HCL as a catalyst along with water

reversible so gives low yeild of CA

22
Q

What is basic hydrolysis?

A

when an ester is hydrolysed into an alcohol and carboxylic salt when heated with an alkali

23
Q

What is the equation for the first step of basic hydrolysis?

A

Add alkali (NaOH)

e.g ethanoic acid

CH3CO|OCH3 + NaO|H > CH3COO-Na+ CH3OH

24
Q

what is the second step of basic hydrolysis?

A

add excess acid (dilute H2SO4 or HCl) and carboxylic acid is reformed

CH3COO-Na + HCL > CH3COOH + NaCl

25
Q

What are triesters?

A

triglycerides of long chain carboxylic acids (fatty acids) and gylcerol

they occur as fats and oils

26
Q

What is formed when triglycerides are hydrolysed?

A

hydrolysed using hot NaOH or KOH

glycerol and sodium/potassium salts of long chain carboxylic acids (carboxylate salts)

27
Q

What are carboxyate salts used for?

A

soap

28
Q

What is biodiesel?

A

liquid fuel consisting of a mixture of methyl Esters of long chain carboxylic acid from vegetable oil

29
Q

how do you Hydrolyse fats/oils into biodiesel?

A

react with a methanol with a strong acid/alkaline as a catalyst

This forms a mixture of methyl Esters

30
Q

What is bio diesel used for?

A

Fuel in diesel vehicle vehicles

31
Q

What are the two functional groups of carboxylic acids?

A

acyl chlorides and acid anhydrides

32
Q

What is a acyl chloride!

A

the -OH group in a carboxylic acid is replaced by a chlorine atom

33
Q

how do you name an acyl chloride?

A

suffix = oyl chloride

Ethanolic acid ethanoly chloride

34
Q

what is the equation for nucleophilic addition elimination?

A

CH3COCl + XH > CH3COX + HCl

35
Q

what are the four different nuclear phases that were react with acyl chlorides?

A

water
alcohol
ammonia
amines

36
Q

What is the name of the mechanism with acyl chlorides?

A

Nucleophilic edition elimination

37
Q

what are the advantages of using acyls to make esters?

A

no catalyst is needed
purer product
High yield because the reaction is not reversible

38
Q

what is a limitation of using acyl chlorides?

A

HCL is toxic and corrosive

39
Q

how amides formed?

A

when acyl chlorides react with ammonia

40
Q

How do you name N-substituted amides?

A

N and the suffix -anamide

41
Q

what is an advantage of using acid anhydrides?

A

cheaper
React less exothermically so the reaction is less violent
Less vulnerable to hydrolysis
HCL is not formed
High yield

42
Q

what forms acid anhydrides?

A

Went to carboxylic acid joined together with the elimination of water

43
Q

how do you name an acid anhydride?

A

-anhydride replace the -acid suffix

44
Q

why are acid anhydrides leave groups good?

A

they activate the adjacent carbonyl group by electron withdrawal

45
Q

what is a good leaving group?

A

A stable species which is removed during a chemical reaction

46
Q

What are the three ways to create carboxylic acids?

A
  • primary alcohols/aldehydes are oxidised by acidified potassium dichromate
  • acyl chloride react with water
  • acid anhydrides with water
47
Q

What are the three way to create an Esther?

A
  • carboxylic acid reacting with an alcohol
  • acyl chloride with alcohol
  • acyl anhydrides with alcohol

Chemistry U6 (6 decks)

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