Question

would you expect the following carboxylic acid to be more acidic or less acidic than benzoic acid? Explain (Reddish brown=Br)

Short answer

To check whether the carboxylic acid is more or less acidic than benzoic acid.

Step-by-step solution

Representation of model is p-bromobenzoic acid(a)

The compound model can be represented as,

The para positive which is present in p-bromobenzoic acid contains bromine is an electron withdrawing group. It will stabilize the anion of p-bromobenzoyate which produces the p-bromobenzoic acid which lose proton both by inductive and resonance effects.

Thus, p-bromobenzoic acid is more acidic compared to benzoic acid.

Representation of model is p-(N,N-dimethylamino) benzoic acid(b)

The compound model can be represented as,

The presence of N,N-dimethylamino group which present in the para positive in p-(N,N-dimethylamino) benzoic acid results in electron releasing group. It can de-stabilize the production of p-(N,N-dimethylamino) benzoyate anion.

Thus, It is more acidic than benzoic acid.

Thus p-bromobenzoic acid is more stable then p-( N,N diethyl amino) benzoic acid.