Carboxylic acids 3.3.9 Flashcards

1
Q

Name three reactions to prepare carboxylic acids

A

Oxidation of primary alcohol under reflux
Oxidation of aldehyde under reflux
Hydrolysis of Nitriles

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2
Q

Describe the reaction (and write the equation) for hydrolysis of nitriles

A

Nitrile is refluxed with water and hydrochloric acid
Produces carboxylic acid and ammonium chloride
R-C≡N + 2H2O + HCl →RCOOH + NH4Cl

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3
Q

What happens when Carboxylic acids dissociate

A

Forms a carboxylate ion RCOO- (negative) and a H+ ion

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4
Q

Is dissociation of carboxylic acids reversible

A

yes

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5
Q

What is the charge of a carboxylate ion

A

Negative

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6
Q

Is the carboxylate ion stable or not - why?

A

Yes
Negative charge is delocalised across the whole carboxylate group

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7
Q

Give the products of the reaction of methanoic acid and sodium carbonate

A

Sodium methanoate. carbon dioxide and water

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8
Q

What is produced when coohs react with carbonates

A

Salt, water and CO2

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9
Q

What is produced when coohs are neutralised

A

Salt and water

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10
Q

What is produced when propanoic acid and sodium hydroxide are reacted together

A

Sodium propanoate and water

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11
Q

What is formed when an alcohol and carboxylic acid react

A

Ester and water

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12
Q

What is the functional group of an ester

A

COO

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13
Q

What type of reaction occurs when an alcohol and carboxylic acid react

A

Condensation

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14
Q

What are the products formed when propanoic acid reacts with methanol

A

Methyl prooanoate and water

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15
Q

What is hydrolysis of esters

A

Splitting up esters using water

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16
Q

What two types of hydrolysis are there

A

Base and Acid

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17
Q

What acids at what strength are used in acid hydorlysis

A

Dilute HCL or H2SO4

18
Q

Ester+Water (with H+) =

A

OH and COOH

19
Q

What does acid hydrolysis produce

A

Alcohol and cabroxylic acid

20
Q

What does base hydrolysis producen

A

Carboxylate ion and alcohol

21
Q

What is the IUPAC name of glycerol

A

propane-1,2,3-triol

22
Q

In what way are fats and lipids esters of glyceorl

A

Glycerol (alcohol) reacts in a condensation to reaction with 3 fatty acids (COOH) to form fatty acids with COO

23
Q

Do saturated fatty acids have double bonds C=C

A

NO

24
Q

What is the difference between fats and oils and why

A

Fats are normally solids at room temperature but oils are liquids at room temperature
Because
Oils are polysaturated whereas fats are unsaturated
So
Molecules of fats get closer together as the chain DOES NOT bend so VdWs are stronger and so fats have a higher MP

25
Q

How is soap formed

A

Hydrolysis of animal fats or vegetable oils (heated with NaOH)

26
Q

What happens when you react a fat/oil with NaOH

A

It forms a sodium salt and glycerol

27
Q

How is biodiesel made

A

React oils with methanol (KOH catalyst)

28
Q

What is biodiesel actually

A

Methyl ester

29
Q

What is formed when yiu react oils with methanol (KOH catalyst)

A

Glycerol and methyl ester

30
Q

Functional group of acyl/acid chlorides

A

COCl

31
Q

Why are COCls susceptible to attack by nuclepphiles

A

in cocl c=o and c-cl bonds are polar

32
Q

What is the reaction called when COCls react with water, nh3 or amines

A

Addition-elimination

33
Q

What is produced when COCl reacts wtih water

A

Carboxylic acid and HCl

34
Q

What is produced when COCl reacts with NH3 nucleophile

A

alkyl amide + NH4Cl

35
Q

What is produced when COCl reacts wtih alcohol

A

Ester + HCl

36
Q

Amine vs Amide

A

Amine is MINE because its noT C=Ool

37
Q

What is produced when acid anhydrides react with water

A

Carboxylic acid

38
Q

What is produced when acid anhydrides react with alcohols

A

Ester and carboxylic acid

39
Q

What is produced when acid anhydrides react with primary amines or NH3

A

Amides

40
Q

Name The industrial advantages of ethanoic anhydride over ethanoyl chloride in the manufacture of the drug aspirin.

A

Ethanoic anhydride is cheaper than ethanoyl chloride.

Ethanoic anhydride is safer to use than ethanoyl chloride. It is less corrosive and not so readily hydrolysed (its reaction with water is slower).

Ethanoic anhydride doesn’t produce dangerous (corrosive and poisonous) fumes of hydrogen chloride

41
Q

Describe how to purify a sample of aspirin

A
  • Dissolve in minimum hot solvent
  • Filter
    -Cool in ice bath
  • Filter using buchner funnel
    -Dry
42
Q
A