Carboxylic acids Flashcards
describe acidity of carboxylic acids
weak acids but stronger than alcohol
why is carboxylic acid weak acid
electron withdrawing group C=O pulls electron towards itself
weakened C-OH bond
delocalisation spreads and ion is stable = lower charge density
stay dissociated
describe acidity of alcohol
electron withdrawing group and donating group present
high charge density at oxygen
colour change for acidified potassium manganate (VII)
purple to colourless
colour change of acidified potassium dichromate (VI)
orange to green
colour change and reaction of fehling’s
Cu2+ → Cu + (red precipitate)
colour change and reaction of tollen’s
Ag+ → Ag (silver precipitate)
which two acids produce water and carbon dioxide when oxidised
ethanedioic and methanoic
conditions for oxidising acids
warm
reflux
oxidising agent
how do you produce acyl chlorides (3)
with PCl5/PCl3 + heat/SOCl2
what are the products when acid + PCl5
acyl chloride + POCl3 + HCl
what are the products when acid + PCl3 + heat
acyl chloride + H3PO3
what are the products when acid + SOCl2
acyl chloride + SO2 + HCl
how do we extract acyl chloride out
fractional distillation
why are acyl chlorides more reactive
O=C-Cl causes carbon to be very positive and open to nucleophilic attack
rate in ease of hydrolysis
aryl chloride
acyl chloride
chloroalkane
acyl chloride > chloroalkane > aryl chloride
reactions acyl chloride undergoes (3)
hydrolysis
reaction with alcohol group
reaction with amines
type of reaction acyl chloride undergoes
addition-elimination
benzoyl chloride + water
carboxylic acid
Ethanoyl chloride + ethanol
→ (ester) ethyl ethanoate + HCl
Ethanoyl chloride + sodium phenoxide ( + conditions)
→ phenyl ethanoate (ester) + NaCl
aq.NaOH + warm
Ethanoyl chloride + ethylamine
→ N-ethylethanamide + HCl
