Why p-nitrobenzoic acid is stronger than M benzoic acid?

“P-nitrobenzoic acid is stronger than benzoic acid.” In the benzoic acid there is a resonance effect which stabilizer is the carboxylic group present in that benzoic acid. Since the intermolecular bond is stronger than the resonance effect the nitro benzoic acid is more stabilized and stronger in acidity parameter.

Why M nitrobenzoic acid is a stronger acid than benzoic acid?

Because the benzoic acid have a resonance effect. But the nitrobenzoic acid have a intermolecular bond. That’s why the nitrobenzoic acid is stronger than the benzoic acid. Nitro group is an electron withdrawing group which increases the acidity of the benzoic acid.

Which is more acidic benzoic acid or p toluic acid?

It is this stabilization provided by the methyl group that makes o-toluic acid a stronger acid (pKa=3.91) than benzoic acid (pKa=4.19).

Why is p-nitrobenzoic acid more acidic than M-nitribenzoate?

When both acids donate their proton from -COOH group then p-nitrobenzoate is more stabilized due to -M effect of nitro group than m-nitribenzoate because -M group more deactivates the ring / decreases charge than -I group. Thus, p-nitrobenzoic acid is more acidic than m-nitrobenzoic acid.

Which is more acidic – benzoic acid or carboxylic acid?

P-nitro benzoic acid is more acidic than benzoic acid, because nitro group have -I effect (electron withdrawing group) due which it withdraws electron toward itself and deactivate the benzene ring to electrophilic attack, therefore, carboxylic acid group easily releases H+ ion than benzoic acid.

Why is orthobenzoic acid a poor acid?

It’s p-nitrobenzoic acid . It’s due the reason that the COOH group and nitro group at Ortho form a inter-molecular H-bonding . Due to this the H+ ion of COOH group can not be removed easily making it a poor acid as compared to p-nitrobenzoic acid .

What is the relationship between pKa and acidic strength of NO2?

Greater the value of PKa lesser will be acidic strength. Actually due to ortho effect and the -I effect operates and also the distance between the NO2 group and COOH group is minimun . O-nitrobenzoic acid (due to ortho effect) > p-nitrobenzoic acid (due to -I effect)>m-nitrobenzoic acid (as meta less effective to show -I effect)>benzoic acid