3.3.9 carboxylic acids and derivatives Flashcards
(24 cards)
how are esters formed?
by the reaction between carboxylic acids and alcohols under reflux with a concentrated sulfuric acid catalyst
what are two ways you can form a diester?
reacting a di carboxylic acid with 2 mol of alcohol
reacting a di alcohol (diol) with 2 mol of carboxylic acid
what are some of the uses of esters?
organic solvent
poly esters (plastics)
natural esters found in pheromones
what are the ways you can hydrolyse an ester?
react ester with acid or alkali in solution under reflux
outline how an acid catalysed hydrolysis happens
using dilute sulfuric acid or HCl under reflux
reversible reaction - will never be 100% yield
what is the ester functional group?
COO
what bond breaks when an ester is hydrolysed?
the C-O single bond
outline how a base catalysed reaction happens
- using dilute sodium hydroxide under reflux (any base can be used)
- forms alcohol and salt of carboxylic acid
- not reversible so better yield and quicker
what can you hydrolyse vegetable oils and animal fats into?
soaps and glycerol
in soaps the salt of the long carboxylic acid acid are used
what is biodiesel?
renewable fuel
made from vegetable oil derived from crops
mixture of methyl esters and glycerol
to make it oil is reacted with methanol to form methyl esters and glycerol in the presence of a catalyst
how does an acyl chloride differ from a carboxylic acid?
OH group replaced by Cl group
what is the suffix of an acyl chloride?
-oyl chloride
i.e ; propanoyl chloride
in the nucleophilic substitution elimination reaction what are the nucleophiles?
H2O, alcohol, ammonia and amine
what is the product of ALL the nucleophilic addition substitution reactions?
HCl
what is observed when HCl is produced?
steamy white acidic fumes
what is produced when an acyl chloride reacts with water?
carboxylic acid and hcl
what is produced when an acyl chloride reacts with ammonia?
amide and HCl
what is produced when an acyl chloride reacts with alcohol?
ester and HCl
what is produced when an acyl chloride reacts with an amine?
n substituted amide and HCl
describe briefly how you could measure the melting point of aspirin
place sample in capillary tube and heat gently
how are acid anhydrides formed?
a reaction of two molecules of a carboxylic acid resulting in an elimination of water
what is the suffix of an acid anhydride?
oic anhydride
explain why acid anhydrides are able to react?
due to polarity, carbons are susceptible to attack by nucleophiles
why is it better to use acid anhydrides than acrylic chlorides?
acid anhydrides are cheaper to produce, less corrosive and produce carboxylic acids which are safer than HCl
