Esters Flashcards
what are esters?
a family of organic molecules which form when a carboxylic acid and alcohol join together by losing a water molecule
when drawing esters where does the ester functional group (-COO-) go?
- it sits between two carbon chains, joining them together
- it doesn’t matter what the other carbon chains look like, so they are represented by question marks in a diagram
when is the ester formed when ethanoic acid and ethanol react?
ethyl ethanoate
what is the reaction between ethanoic acid and ethanol called?
condensation - because of the production of water vapour
(sometimes it is called esterification because it makes an ester)
how to make an ester
to prepare an ester, you would:
- mix the carboxylic acid and alcohol together
- add a few drops of concentration sulfuric acid - this acts as a catalyst for the reaction
- warm it for a whole
- tip the mixture into sodium carbonate solution - this neutralises the sulfuric acid catalyst, which is otherwise really corrosive (the reaction produces carbon dioxide so you wait until the fizzing has stopped)
what are esters used for and why?
esters are volatile compounds with distinctive smells that make them suitable for use in food flavourings and perfumes
how do you choose the correct carboxylic acid and alcohol to make a particular ester?
you draw it and then split it down the middle where the oxygen atom is in line with the carbon chain