esters Flashcards
what are the function group of esters
‘RCOOR’
define alkyl
carbon chain of unknown length
what are the products formed in the reaction of :
ethanoic acid + propanol
ethanoic acid + propanol —> propyl ethanoate + H20
give 2 ways esters are different to carboxylic acids
esters have an organic group attached to O instead of H
esters are insoluble in water so no Hydrogen bonding
how do you name esters
ester always puts her alcohol first
name the ester formed in the reaction between:
- methanoic acid and ethanol
- propanol and ethanoic acid
- ethanol and ethanoic acid
- ethyl methanoate
- propyl ethanoate
- ethyl ethanoate
what 3 things are esters useful as
flavourings (rum - 2-methylpropylpropanoate)
solvents (nail varnish remover - ethyl ethanoate)
plasticisers
what conditions are needed to make an ester from a carboxylic acid and an alcohol
reflux
with strong acid (HCl , H2S04)
why is H2SO4 the preferred acid for the reflux of a carboxylic acid and an alcohol to form an ester
H2SO4 has twice as many protons so speeds up the reaction quicker
write the symbol and word equation for the reflux of propanoic acid and ethanol in the presence of H2SO4
propanoic acid + ethanol —> ethyl propanoate + water
CH3CH2COOH + CH3CH2OH —> CH3CH2COOCH2CH3 + H20
why can H2SO4 be described as a dehydrating agent in the reaction of an carboxylic acid and an alcohol
H2SO4 is a dehydrating agent as it removes water causing equilibrium to move to the right which increases the yield of ester
define hydrolysis reaction
reaction with water or OH- ions that breaks a compound in 2
when neutral:
ester + water ⇌
ester + water ⇌ carboxylic acid
when neutral finish the equation:
ethyl methanoate + water ⇌
ethyl methanoate + water ⇌ methanoic acid + ethanol
when in the presence of HCl (aq)
methyl ethanoate —>
methyl ethanoate —> ethanoic acid + methanol
