[chrisjohns]

A stock solution is 40% CaCl2  (w/v). Assuming that the solution contains 999.0ml of water, at what temperature will the solution boil? Density of water is 1.00g/ml. Kb=0.52°C/molal

I know the formula to use is ?Tb= m x d.f. x kb where m= molality of the solution, d.f.= dissociation factor and kb for H2O = 0.52°C/m.

My question is whether CACl2 is considered an electrolyte making the d.f= 2, or is it a non electrolyte making d.f.=1? Also, can I assume that because the density of H2O is 1.00g/ml that the water solvent of 999.0ml can be converted to 999g then to 999000kg as the denominator in the molality portion of the equation?

[Yggdrasil]

In general, ionic compounds are considered electrolytes so they dissociate in solution and have a d.f. > 1.  Covalent/molecular compounds are non-electrolytes in general.

Now, CaCl₂ is an ionic compound, so it will dissociate in water.  But, its d.f. is not 2.

Also, most of your calculations about the volume and mass of water are correct, but 999g = 0.999kg, not 999000kg.