3.3.9 Carboxylic acids and derivatives (A2) Flashcards
what is the functional group of carboxylic acids?
R-COOH
what is the pH of carboxylic acids?
weak acids - pH 3-6
what is the name of a carboxylic acid which includes a benzene ring?
benzanoic acid
can carboxylic acids form H bonds with water? what does this mean?
yes
carboxylic acids with up to and including 4 carbons are completely soluble in water
when can carboxylic acids form H bonds with eachother?
in the solid state
what do the H bonds account for in terms of properties?
much higher boiling point than their counterpart alkanes
what is mechanism is likely to happen in carboxylic acids? why?
nucleophilic addition
delta positive carbon is very susceptible to nucleophilic attack and addition reactions are likely to happen as there is an area of unsaturation
what happens to carboxylic acids in solution?
partially ionised
forms carboxylate ion and a proton (H+)
what is the chemical reactivity of carboxylic acids?
despite being weak acids, any carboxylic acid will still react with sodium hydrogencarbonate (NaHCO3)
what happens in the reaction between sodium hydrogen carbonate (NaHCO3) and a carboxylic acid?
releases carbon dioxide
we would see bubbling
what can we use to distinguish between carboxylic acids and alcohols?
sodium hydrogencarbonate
carboxylic acid bubbles
alcohol gives no reaction
what do we use the test with sodium hydrogencarbonate to do?
distinguish between carboxylic acids and alcohols
carboxylic acids bubble - release of CO2
and alcohols give no reaction
what are carboxylic acids in a reaction?
proton donors
what are the salts produced by the reactions of carboxylic acids called generally?
carboxylate salts
what would a reaction of a ethanoic acid produce as a salt?
ethanoate salts
what salt would be produced from a reaction involving methanoic acid?
methanoate salts
what does the reaction of ethanoic acid and sodium hydroxide produce?
sodium ethanoate and water
what does a reaction between propanoic acid and aqueous sodium carbonate produce?
sodium propanoate
water
carbon dioxide
do carboxylic acids ionise partially or completely in water?
partially ionise in solution
what is the charge on a carboxylate ion called?
delocalised electron charge
what is the functional group of an ester?
RC=OO-R’
what are esters used for?
cleaning products, perfumes, flavourings
how do we form an ester?
carboxylic acid + alcohol
what is the equation for forming an ester?
carboxylic acid + alcohol –> ester + water
how would we get a higher yield of ester from the carboxylic acid + alcohol reaction?
increase volume of carboxylic acid / alcohol
remove water is it is formed
how can we get the carboxylic acid and alcohol back from the ester?
hydrolysis
what does an addition elimination reaction of an ester form?
carboxylic acid
alcohol
what conditions does an addition elimination reaction involving an ester?
room temperature
acid catalyst