Question

1a) Why can Methanol not be used as a solvent with water as the other solvent in extraction.

1b) explain why multiple extractions with smaller volumes of the extractionsolvent are typically better than single extractions with larger volume of the solvent.

1c) Benzoic acid is a much stronger acid than the weak acid phenol (C₆H₅OH) consequently benzoic acid reacts with the weak base sodium bicarbonate, NaHCO₃, while phenol does not. Suggest a scheme for the total separation of the three compounds in a mixture of benzoic acid, phenol, and naphthalene using this information. Use structures with formal charges for full credit.

Answer 1

1a)

methanol is retty soluble in water, therefore it is not recommended for an extraction

1b)

this is typically better since we increase the stages of equilibrium, therefore small amounts of product is obtained, but the change in gradient helps.

1c)

benzoic acid + phenol and naphtalene

add ether + NaHCO3

this separates:

organic layer --> phenol + naphtalene

aquous layer ocntinas acid

add NaOH to rganic layer

naphtalene remains in organic layer

finally, the aquous solution from this will contain phenol