Carboxylic acids and derivatives Flashcards
(15 cards)
Carboxylic acid functional group
R - C =0
|
OH
bonding in carboxylic acids: how it affects solubility and boiling point
- Carboxylic acids can hydrogen bond
Solubility decreases with increasing chain length:
* the carboxylic acid becomes more alkane in nature
* becomes more hydrophobic and more non-polar
Differences in boiling point between alcohols, carboxylic acids and alkanes
alkanes< alcohols< carboxylic acids
- all 3 have London forces
- carboxylic acids and alcohols have hydrogen bonding
- carboxlyic acids have more electrons so stronger London forces
Methods of making carboxylic acids
1. Oxidisation of alcohols
CH₃CH₂OH + [O] –> CH₃COOH + H₂O
2. Oxidisation of aldehydes
CH₃CHO + [O] –> CH₃COOH
3. Hydrolysis of nitriles
-ACIDIC- (heated under reflux with dilute HCl)
CH₃CN + 2H₂O + HCl(aq) –> CH₃COOH + NH₄Cl
-ALKALI- (heated under reflux with NaOH)
CH₃CN + H₂O + NaOH –> CH₃COONa + NH₃(g)
* to get a free carboxylic acid here, acidify final solution with strong acid
nitrile –> amide –> carboxylic acid
Reactions of carboxylic acids: Acid base reactions
- Carboxylic acids are weak acids
General equation:
carboxylic acid + base —> salt + water
ex. methanoic acid and sodium hydroxide
HCOOH + NaOH —> HCOO-+Na + H₂O
Reactions of carboxylic acids: lithium tetrahydridoaluminate (lithium aluminium hydride) in dry ether
Reactions of carboxylic acids: phosphorus (V) chloride (phosphorus pentachloride)
Reactions of carboxylic acids: alcohols in the presence of an acid catalyst
Ester functional group
R-C=O
|
O
|
R
Acyl chloride functional group
R-C=O
|
Cl
Acyl chloride reactions: water
Acyl chloride reactions: alcohols
Acyl chloride reactions: concentrated ammonia
Acyl chloride reactions: amines
Hydrolysis of esters in acidic and alkali solution
How are polyesters formed by condensation polymerisation reactions?
