3.9 Caboxylix acids and derivatives

Question 1

How acidic are carboxylic acids?

Answer 1

The carboxylic acid are only weak acids in water and only slightly dissociate, but they are strong enough to displace carbon dioxide from carbonates.

Question 2

How soluble are carboxylic acids in water?

Answer 2

The smaller carboxylic (up to C4) acids dissolve in water in all proportions but after this the solubility rapidly reduces. They dissolve becausetheycanhydrogenbondto the water molecules.

Question 3

If there are carboxylic acid groups on both ends of the chain then it is called a…

Answer 3

dioic acid

Question 4

How are carboxylic acids delocalised?

Answer 4

The carboxylic acid salts are stabilised by delocalisation, which makes the dissociation more likely.

The delocalised ion has equal C-O bond lengths. If delocalisation did not occur, the C=O bond would be shorter than the C-O bond.

The pi charge cloud has delocalised and spread out. The delocalisation makes the ion more stable and therefore more likely to form.