Esters Flashcards
What are the properties of esters?
They are volatile (vaporise easily), have a fruity smell and are used in food flavourings and perfumes.
What is the reaction to make an ester?
Condensation or esterification
How to name an ester?
First is the alcohol and then the acid;
_______yl_______anoate.
What is the reaction of an ester?
Carboxylic acid + Alcohol ——> Ester + Water
What parts of the alcohol and acid make water?
The OH from the acid and the H from the hydroxyl group of the alcohol.
The remaining parts join to form the ester
What is the definition of a condensation reaction?
A condensation reaction is one where two small molecules join to form one larger molecule and another small molecule such as water
What is the catalyst in a condensation reaction?
Concentrated Sulphuric Acid
Why is the esterification reaction placed in a hot water bath?
Because the alcohol is flammable under a Bunsen burner
Why is a wet paper towel used around the test tube during esterification?
To act as a condenser (cool it down)
Why is a cotton wool plug used during a condensation reaction?
To stop all vapour
What is the esterification reaction poured into and why?
It is poured into sodium (hydrogen) carbonate to neutralise the acid catalyst as they are not used up in a reaction
What layer is on top of an ester?
A thin immiscible layer of oil (has the distinctive fruity smell)
What are the signs of an ester being made?
Fruity smell, made Carbon Dioxide (fizzed) and an oil layer
How do you break an ester and what is broken?
Hydrolysis which breaks the ester link
What is a hydrolysis reaction?
A hydrolysis reaction is where a larger molecule is split into two smaller molecules by reaction with a very small molecule like water
