carboxylic acids, acyl chlorides, esters Flashcards
why are longer carboxylic acids less soluble in water?
The solubility of the bigger acids decreases very rapidly with size. This is because the longer hydrocarbon “tails” of the molecules get between water molecules and break hydrogen bonds. In this case, these broken hydrogen bonds are only replaced by much weaker van der Waals dispersion forces.
carboxylic acids + reactive metals in redox reaction….
- salt
- hydrogen gas.
carboxylic acids w/ carbonates
- salt + water + co2
carboxylic acids + bases ?
- neutralisation
- salt + water
what is the functional group of acyl chlorides
-OCl
what is general formula of acyl chlorides?
HnH2-1OCl
reagent + conditions + product c.box acid -> acyl chloride
- SOCl2
products are acyl chloride + SO2 + HCl
what are the 4 reactants that react w/ acyl chlorides?
- water
- alcohol
- ammonia
- amines
describe reaction of acyl chloride w/ water?
- vigouros reaction
- c.box formed
- HCl formed
describe reaction of acyl chloride w/ alcohol?
- vigorous reaction
- ester formed
- HCl formed
describe reaction of acyl chloride w/ ammonia ?
- primary amide
- violent reaction
- HCl formed
describe reaction of acyl chloride w/ amines?
- violent reaction
- prod secondary amide
- HCl formed
what type of reactions do acyl chloride go through?
- nucleophilic addition elimination.
- Cl is substiuted by O2,Nitrogen groups.
HCL fumes given off.
ester formation by carboxylic acid
- heat alcohol with carboxylic acid
- presence of H2SO4 or acid catalyst.
- REVERSIBLE
is esterification by carboxylic acid + alcohol reversible or not?
yes
how do u separate larger esters formed by esterification of c.box + alcohol.
- fractional distillation
- reflux
what is an acid anhydride?
- carboxylic acid derivative made up of 2 carboxylic acids
how do u form ester w/ acid anhydride?
- acid anhydride
- no catalyst needed
- no reflux.
- separate by fractional distillation.
products of acid anhydride + alcohol.
alcohol + carboxylic acid.
how do u form an ester from acyl chloride + alcohols?
what is the product?
- acyl chloride
- H-Cl
acid hydrolysis of esters products?
- ethanoic acid
- ethanol
which type of hydrolysis is reversible?
- acid hydrolysis
what conditions are needed for acid hydrolysis of esters?
- dilute acid (H+)
- reflux
what conditions are needed for base hydrolysis of esters?
- dilute alkali
- NaOH
- reflux.
what is formed in base hydrolysis ?
- sodium ethanoate
- ethanol .
