Answer to 3A:

Answer to 3B:

select SoluteMass * Kf * 1000 /
                           (ChemExperiment.SolventMass * FP)
from ChemExperiment, ChemSolvent
where ExpNumber = 37 and
          ChemExperiment.SolventName =
                ChemSolvent.SolventName;

Answer to 3C:

select KnownCompound
from ChemKnowns
where MolecularWeight >=
      (ExpMW = select SoluteMass * Kf * 1000 /
                             (ChemExperiment.SolventMass * FP)
          from ChemExperiment, ChemSolvent
          where ExpNumber = 5 and
                 ChemExperiment.SolventName =
                        ChemSolvent.SolventName) - 5
         and MolecularWeight <= ExpMW + 5;