carboxylic acids & derivatives [O2] PAPER 2 Flashcards
general structure of a carboxylic acid?
esterification/ester hydrolysis reaction and conditions?
• alcohol + carboxylic acid ⇌ ester + water
• above the other way round = ester hydrolysis (in acidic conditions)
• concentrated strong acid catalyst, e.g. H2SO4
e.g.
saponification reaction?
• ester + alkali → salt of carboxylic acid + alcohol
• this is ester hydrolysis in alkaline conditions
common uses of esters?
• food flavourings
• perfumes
• solvents
• plasticisers
structure of glycerol (propan-1,2,3-triol) ?
Vegetable oils and animal fats are naturally occurring esters of glycerol.
Reaction that glycerol undergoes with three fatty acids (long C chain carboxylic acids) to form a triglyceride ester?
production of biodiesel reaction?
• transesterification
• lipid + methanol → 3 methyl esters of fatty acids + glycerol
• catalyst needed
saponification of a lipid?
lipid + 3KOH → 3 salts of fatty acids + glycerol
general structure and naming of an ester?
red = carboxylic acid
yellow = alcohol
[alcohol]yl [carboxylic acid]oate
general structure of an acid anhydride?
general structure of an acyl chloride?
name and outline the mechanism for the acylation of R—OH using R—COCl.
nucleophilic addition-elimination
name and outline the mechanism for the acylation of R—NH2 using R—COCl.
nucleophilic addition-elimination
Separate samples of each isomer are warmed with ethanoic acid and a few drops of concentrated sulfuric acid. In each case the mixture is then poured into a solution of sodium hydrogencarbonate.
Identify the isomer(s) that would react with ethanoic acid.
Suggest a simple way to detect if the ethanoic acid reacts with each isomer.
Give a reason why the mixture is poured into sodium hydrogencarbonate solution.
• P, Q, R, S
• sweet smelling liquid
• to react with excess acid
