3.3.9.1 Carboxylic Acids and Esters Flashcards
What intermolecular forces occur between carboxylic acid molecules?
Hydrogen bonding with water molecules
Also hydrogen bonding with each other when in a solid state
What are esters derived from?
Carboxylic acids where the hydrogen is replaced by a hydrocarbon group
What is the general formula of an ester?
RCOOR’
How do you name an ester?
They’re based on the name of the parent acid
e.g. all esters from ethanoic acid are called ethanoates
The name always begins with the group that has replaced the hydrogen of the acid
e.g. CH3 - C( = O) - O - CH3 is called methyl ethanoate
What are the properties of esters?
Short chain esters are fairly volatile
How does a carboxylic acid react with sodium hydrogencarbonate?
The H+ is removed from the OH group and replaced by a sodium ion
This forms a salt, water and carbon dioxide
What is the reaction between a carboxylic acid and an alcohol?
Carboxylic acid + alcohol = ester + water
Requires a strong acid catalyst
Reversible reaction
Backwards reaction: hydrolysis of esters, base acts as a catalyst
What are vegetable oils and animal fats esters of?
Propan-1,2,3-triol (glycerol)
What is the difference between fats and oils?
Fats are solid
Oils are liquid
What type of molecules are oils and fats?
Triglycerides
How can fats and oils be hydrolysed?
In acid conditions
Or by boiling with sodium hydroxide
