Carboxylic acids and derivatives Flashcards
Describe the term weak acid
weak acids do not fully dissociate into H+ ions in solution. The equilibria lies far to the left. Carboxylic acids are examples of weak acids
how are carboxylic acids produces`
by the oxidation of aldehydes
what is formed when carboxylic acids react with alkalis
a salt and water will be formed. the suffix of the salt formed is -oate
give the name of the organic product formed when ethanoic acid is reacted with NaOH
sodium ethanoate
what is formed when carboxylic acids react with hydrogencarbonates
a salt, water and carbon dioxide
what is formed when carboxylic acids react with alcohols
and ester and water. this process is esterification
give the organic product formed from the reaction of methanol with ethanoic acid
methyl ethanoate
what are the products of the hydrolysis of esters
carboxylic acids and alcohols
why is this reaction very slow
because water is a poor nucleophile
give the products of acid catalysed hydrolysis of esters
the carboxylic acid and alcohol
give the products of base catalysed hydrolysis of ester
the carboxylate salt and alcohol
why is the carboxylate salt formed from base catalysed hydrolysis useful?
it is used to make soaps
give three uses of esters
- artificial perfumes and flavourings
- as plasticisers. plasticisers weaken the intermolecular forces between polymer chains
- used as solvents. short chain esters are volatile
- as Biodiesel- a mixture of methyl esters. it is made from crops like rapeseed, which is reacted with methanol and an alkali catalyst to form a mixture of methyl esters
what is the suffix for acyl chlorides and what is their functional group
- oyl chloride
- functional group is O=C-Cl
give the structural formula for propanamide
CH3CH2CHONH2
name the two products when an acyl chloride reacts with water
you get HCl and the corresponding carboxylic acid
name the mechanism that occurs when a nucleophile reacts with a acyl chloride
addition-elimination reaction.
The acyl chloride is highly susceptible to attack by the nucleophile, due to its highly electron deficient carbonyl group, because of the electron withdrawal from the electronegative chlorine
what will be produced when an acyl chloride reacts with NaOH in solution
the carbonyl salt will be produced, instead of the carbpoxylic acid
what is formed by reacting an acyl chloride with an alcohol
an ester is formed
how could you remove the HCl that is produced
by adding a base like NaOH
what is produced by reacting an acyl chloride with a primary amine
an N-substituted amide is produced. If you have excess of the amine, the Cl- ion will be attracted to the N+ on the NH3+, forming an alcyl ammonium salt
what is formed by the reaction between an acyl chloride and ammonia?
an amide.
why might an excess of the ammonia be used?
to remove the HCl that is formed
what are the products formed by reacting an acid anhydride with an alcohol
an ester an a carboxylic acid
what is produced when an acid anhydride is reacted with water
two carboxylic acids
write a word equation for the formation of Aspirin
2-hydroxy bezoic acid + ethanoic anhydride –> aspirin + ethanoic acid
describe how aspirin is purified
- dissolve the impure product in a hot solvent
- use a minimum amount of solvent, to produce a saturated solution
- filter the solution to remove any solid impurities
- cool to recrystallise
- filter under reduced pressure using a buchner funnel
- wash using a cold solvent to remove any impurities on the surface, and dry
