Question

What would the boiling point be of 300 ml with 40 g CuCl2 dissolved in it?

Answer 1

300 mL of what? H2O? If so the following will do it. If not H2O, then change the Kb constant and everything else is the same except you will need the density to convert mL to grams of the solvent.

mols CuCl2 = grams/molar mass
Solve for mols.

molality = mols/kg solvent
Solve for m

delta T = i*Kb*m
i = van't Hoff factor = 3 for CuCl2

Then add the value of dT to the normal boiling point of H2O.