Question

To my understanding, both have analogous resonance structures except that the ester has on -OR and the carboxylic acid has an -OH. Why is a positive charge on C-O-R more stable than on C-O-H?

Answer 1

The positive charge on C-O-R in an ester is more stable than on C-O-H in a carboxylic acid due to resonance.

Step-by-step explanation:

The positive charge on C-O-R in an ester is more stable than on C-O-H in a carboxylic acid due to the resonance effect. In esters, the carbonyl carbon is bonded to an oxygen, which is itself bonded to another carbon. This creates a delocalization of the positive charge through resonance, making the positive charge more stable.

In contrast, in carboxylic acids, the carbonyl carbon is bonded to an oxygen, which is itself bonded to a hydrogen. There is no additional carbon for resonance to occur, resulting in a less stable positive charge on the oxygen.