Carboxylic Acids and its derivatives Flashcards
What are carboxylic acids reduced to?
Aldehydes
Are carboxylic acids weak or strong?
Weak
What is a test for carboxylic acids?
Add a named carbonate such as Na2CO3, and bubbles of CO2 will be produced
Give a formulaic equation to show what happens when a carboxylic acid is reacted with Na2CO3
RCOOH + Na2CO3 –> RCOO-Na+ (salt of carboxylic acid) + CO2 + H2O
An ester is formed from an alcohol and carboxylic acid in a process called ____
Esterification
Which reactants and catalyst are required for esterification?
Alcohol and carboxylic acid
Conc. H2SO4 catalyst
What is the general formula for an ester?
RCOOR
Esterification produces an ester. What else is produced?
H2O
What is the suffix for esters?
-anoate
How do you name an ester?
RO- alkyl group from alcohol followed by RC=O carboxylate from the acid
What were the reactants used to produce methylethylmethanoate?
Methanoic acid
propan-2-ol
How can the esterification reaction be reversed?
By acid or alkali hydrolysis
What is the difference in products of acid and alkaline hydrolysis?
Acid - alcohol and carboxylic acid
Alkaline - alcohol and salt of carboxylic acid
Triglycerides are sters of what?
Glycerol with fatty acids
Give an example of a reactant that could be used to turn an ester into a carboxylate salt and an alcohol
NaOH
(alkali)
What is IUPAC name for glycerol?
propane-1,2,3-triol
Give a use for glycerol
Used in cosmetics, foods and glues to stop them drying out
Give a use for the salts of fatty acids
Soap
State what is meant by the term ‘biodiesel’
A clean burning renewable fuel made using natural vegetable oils and fats
What reactant, when added to triglycerides, produces glycerol and FAMEs?
3CH3OH
(an alcohol)
State what is meant by ‘acylation’
A reaction in which the acyl group (RC=O) is introduced into another molecule by replacing a H atom
Which two types of molecules can perform acylation?
Acyl chlorides and acid anhydrides
What is the general formula and suffix of acyl chlorides?
RCOCl
-anoyl chloride
What is the general formula and suffix of acid anhydrides?
-anoic anhydride
What is the leaving group (X) of an acyl chloride and what does it go on to make?
Cl
HCl
What is the leaving group of an acid anhydride (X) and what does it go on to make?
RCOO-
RCOOH
What are the conditions for the acylation of water to give carboxylic acids?
Room temp. and pressure
Give the general formula for the acylation of water to give carboxylic acids
RCOX + H20 –> RCOOH + HX
What are the conditions for the acylation of alcohols to esters?
Anhydrous room temp and pressure
What are the conditions for the acylation of ammonia to amides?
Anhydrous room temperature and pressure
What are the conditions for the acylation of primary amines to N-substituted amides?
Anhydrous room temperature and pressure
Give the general formula for the acylation of primary amines to N-substituted amides
RCOX + 2R’NH2 –> RCONHR’ + R’NH3+X-
Give the general formula for the acylation of ammonia to amides
RCOX + 2NH3 –> RCONH2 + NH4+X-
Give the general formula for the acylation of alcohols to esters
RCOX + R’OH –> RCOOR’ + HX
Give the functional group and suffix of an amide
RC=ONH2
-anamide
Give the functional group and nomenclature procedure for an N-substituted amide
NHR (H of NH2 substited for C chain)
N-(C chain) first, followed by the ‘other side’ as such - for which you count the first C as the one with the C=O
Acylation involves what type of reaction mechanism?
Nucleophilic addition-elimination
What is the functional group of acid anhydrides?
RCOOCOR’
A student checks the melting point of their lab made aspirin to indicate its purity. State two observations that would indicate the sample is not pure
The sample has a lower melting point than the data book value
The sample will melt over a wider range of temperatures
The melting point of aspirin may indicate its purity. Suggest why the melting point may be different from the data book value even if the sample is pure
Inaccurate thermometer
The temperature at the bulb of the thermometer may not be that of the sample
What are the industrial advantages of using ethanoic anhydride rather than ethanoyl chloride in the manufacture of aspirin?
Ethanoyl chloride produces HCl gas which is toxic and an irritant, and is more expensive
What is a common use of esters?
Solvents
Plasticisers
Perfumes
Food flavouring
Describe the mechanism of the nucleophillic addition-elimination mechanism of ethanoyl chloride with water.
Describe the mechanism of the nucleophillic addition-elimination mechanism of ethanoyl chloride with ethanol.
Describe the mechanism of the nucleophillic addition-elimination mechanism of one ethanoyl chloride with one ammonia.
Describe the mechanism of the nucleophillic addition-elimination mechanism of one ethanoyl chloride with one ethanamide.
What two reactants form aspirin?
Salacylic acid (2-hydroxybenzoic acid) and ethanoic anhydride to form aspirin and ethanoic acid.
