QJEEM04Ch5c4e: JEE Main 2004 Chemistry - Class 11 JEEM04Ch5c4e Solution: Consider the acidity of the carboxylic acids: (a) PhCOOH (b) o…

In aromatic acids presence of electron withdrawing substituent e.g. $$-N{O}_2$$ disperses the negative charge of the anion and stablises it and hence increases the acidity of the parent benzoic acid.

Further $$O$$- isomer will have higher acidity than corresponding $$m$$ and $$p$$ isomers. Since nitro group at $$p$$-position have more pronounced electron withdrawing than $$-N{O}_2$$ group at $$m$$-position hence the correct order is the one given above.