6.1.3 Carboxylic Acids And Esters Flashcards
Why are carboxylic acids soluble
C=O and O-H bonds are polar, can form hydrogen bonds with water molecules
Solubility decreases with increasing carbon chain
What reactions do carboxylic acids undergo
Redox (with metals) and neutralisation (with bases; alkalis, metal oxides, and carbonated)
Carboxylic acid plus metal
Redox reaction, hydrogen gas and carboxylate salt produced
Carboxylic acids plus metal oxide
Salt and water
Carboxylic acid plus alkali
Salt and water
Carboxylic acid plus carbonate
Salt, water, and carbon dioxide
How to carry out acid hydrolysis
Heat ester under reflux with dilute aqueous acid
Water breaks down the acid
How to carry out alkaline hydrolysis
Heat under reflux with aqueous hydroxide
Forms carboxylate and alcohol
Irreversible
How to prepare an ester (3 ways)
Carboxylic acid plus alcohol in presence of concentrated H2SO4
Acid anhydride plus alcohol
Acyl chloride plus alcohol
How to prepare an acyl chloride
Add carboxylic acid to thionyl chloride (SOCl2)
Forms SO2 and HCl as gases, harmful products so carry out in fume cupboard
Acyl chloride and acid anhydride reaction with phenol
Can undergo as they are more reactive than carboxylic acids, no acid catalyst needed
Ester and hydrogen chloride produced
Acyl chloride reaction with water
Carboxylic acid and hydrogen chloride formed
Very violent reaction
Acyl chloride plus ammonia or amines
Amides formed
Ammonia = primary amide
Primary amine = secondary amide
Reactivity of acid anhydrides vs acyl chlorides
Acyl chlorides more reactive
Solubility in carboxylic acids
C=O and O-H bonds are polar, can form hydrogen bonds with water molecules
Solubility decreases as carbon chain increases
What reactions can carboxylic acids undergo
Redox reactions with metals
Neutralisation reactions with bases (alkalis, metal oxides, and carbonates)
Reaction of carboxylic acid and metal
Redox reaction
Hydrogen gas and carboxylate salt formed
Metal disappears, effervescence
