Question
Chemistry Question on Alcohols, Phenols And Ethers
Explain why is ortho nitrophenol more acidic than ortho methoxyphenol.
Answer
The nitro-group is an electron-withdrawing group. The presence of this group in the ortho position decreases the electron density in the O-H bond. As a result, it is easier to lose a proton. Also, the o-nitro phenoxide ion formed after the loss of protons is stabilized by resonance. Hence, ortho nitrophenol is a stronger acid. On the other hand, the methoxy group is an electron-releasing group. Thus, it increases the electron density in the O-H bond and hence, the proton cannot be given out easily. For this reason,ortho-nitrophenol is more acidic than ortho-methoxyphenol.