Purification technique for crystalline organic solids is known as recrystalization. For recrystallization of naphthalene, the polar solvents such as water and ethanol are bad solvents. On the other hand, the non polar solvents such as benzene, hexane, etc are good solvents for non polar solids like naphthalene.
Answer: HEXANE is a more effective solvent for the recrystallization of naphthalene.