Question: is 2 naphthol soluble in diethyl ether?
Answer: Benzoic acid has a pKa of 4.17, while 2-naphthol has a pKa of 9.5. ... Since benzoic acid's pKa is lower than 6.4, it will deprotonate and become soluble in water, while 2-naphthol will remain in the ether because it won't deprotonate.