26.3 Carboxylic Acids Flashcards
What is the functional group of carboxylic acids? Draw its structure:
carboxyl group
Which 2 groups does a carboxyl group consist of?
Hydroxyl (-OH) + Carbonyl (-C=O)
How does the solubility of carboxylic acids change as the carbon chain increases?
-
longer chain carboxylic acids are less soluble -
- non-polar carbon chain has increasing effect on overall polarity of the molecule
- molecule becomes less polar with a longer carbon chain
- so less hydrogen bonds formed
- so less soluble
Carboxylic acids with up to ____ carbon atoms are soluble in water.
4
How many hydrogen bonds can a single carboxylic acid molecule with 1 carboxyl group form?
3 hydrogen bonds
Why is sodium ethanoate written with charges on the sodium & oxygen? e.g CH3COO-Na+
bonding between oxygen anion & sodium cation is ionic.
writing the charges emphasises that the bonding between Na+ and O- is not covalent.
(when drawing displayed formula, do not put a line between Na+ and O-, as this suggests it is covalent)
Are carboxylic acids weak or strong acids?
weak
Carboxylic acid + Metal ⟶ Carboxylate salt + Hydrogen
What type of reaction is this?
redox
Carboxylic acid + Metal ⟶
carboxylate salt + hydrogen
Carboxylic acid + Metal oxide ⟶
Carboxylate salt + Water
Carboxylic acid + Alkali ⟶
Carboxylate salt + Water
Carboxylic acid + Metal carbonate ⟶
Carboxylate salt + Carbon dioxide + Water
(can be derived from acid + metal carbonate ⟶ salt + carbon dioxide + water)
What is the test for the carboxyl group?
+ metal carbonate, e.g sodium carbonate, Na2CO3
effervesces, due to release of CO2 gas
What is a carboxylate ion?
carboxylic acid, with H+ removed from the hydroxyl group
Draw the corresponding carboxylate ion of this carboxylic acid:
