Question

3 multiple choice 1 point during recrystallization, why is a mixed solvent system (methanol:water) used? methanol reduces the melting point of naphthalene water reacts with naphthalene to purify it naphthalene is soluble in hot methanol but poorly soluble in water naphthalene dissolves only in pure water

Explanation:

In recrystallization, a mixed - solvent system is used when a compound (naphthalene here) is soluble in one hot solvent (methanol) and poorly soluble in the other (water). Cooling the solution causes the compound to precipitate out as pure crystals. Methanol doesn't reduce naphthalene's melting point in this context, water doesn't react with naphthalene for purification, and naphthalene doesn't dissolve only in pure water.

Answer:

C. Naphthalene is soluble in hot methanol but poorly soluble in water