esters

Question 1

what are esters?

Answer 1

a family of organic molecules which form when a carboxylic acid and an alcohol join together by losing a H2O molecule

Question 2

what is the ester functional group?

Answer 2

COO

Question 3

where does the ester functional group (COO) sit?

Answer 3

sits between 2 carbon chains, joining them together

Question 4

carboxylic acid + alcohol ->

Answer 4

ester + water

Question 5

what is the ester formed from ethanoic acid and ethanol reacting together?

Answer 5

ethyl ethanoate

Question 6

what is this reaction sometimes called and why?

Answer 6

condensation because of the production of water vapour

Question 7

what is the reaction sometimes called and why?

Answer 7

esterification because it makes an ester

Question 8

how would you prepare an ester? ( 4 steps)?

Answer 8

1) mix the carboxylic acid and alcohol together
2) add a few drops of concentrated sulfuric acid (H2SO4) - this acts as a catalyst for the reaction
3) warm it for a while
4) tip the mixture into sodium carbonate (Na2CO3) solution- this neutralises the sulfuric acid catalyst which is otherwise really corrosive
this reaction produces CO2 (g) so you wait until the fizzing has stopped

Question 9

why are esters suitable for use in food flavourings and perfumes?

Answer 9

they are volatile compounds with distinctive smells

Question 10

how to choose the correct carboxylic acid and alcohol to make a particular ester?

Answer 10

draw it out and split it down the middle where the oxygen atom is in line with the carbon chain