Flashcards in Carboxylic Acids And Esters Deck (10):
What type of reaction is the formation of esters from carboxylic acids and alcohol
Condensation as a water molecule is eliminated
The H comes the from the alcohol
The O-H from the carboxylic acid
How are esters named?
The alcohol portion is at start of name( right when drawn)
The carboxylic acid is at end of name( left when drawn)
What are the properties of esters?
Low boiling points and are less soluble in water than carboxylic acids as they don’t form hydrogen bonds
They’re sweet smelling liquids which occur naturally in fruit
What are the uses of esters and how we they suited for this
Solvents as esters are polar liquids so lots of polar organic compounds will dissolve in them
Plasticisers allow materials to become more flexible and smooth
What are the 3 different ways esters can be prepared?
Carboxylic acid and an alcohol
Acid anhydride and an alcohol
Acyl chloride and an alcohol
What’s a key thing to remember in condensation between acid anhydrides or acyl chlorides
It’s what forms the main product that attaches to the carbonyl group
The carbonyl is important in determining the structure and often Hs are just removed
Why is ethanoic anhydride used rather than ethanoyl chloride in the manufacture of aspirin?
It is cheaper
It’s less corrosive
It doesn’t react with water as easily ( reacts more slowly with water)
Safer byproduct - ethanoic acid rather than HCl
What are the conditions if the acid hydrolysis of esters?
Reflux with dilute HCl or H2SO4 and HCL(aq)
It forms carboxylic acid and alcohol it is a non reversible reaction
What is involved in the alkaline hydrolysis of esters?
An alcohol is formed and a carboxylate salt
Reflux with NaOH or KOH(aq)
The O-Na+goes to the carbonyl to form the carboxylate salt.