posted by Tim on .
If the molality of a CaCl2 solution is .100 mol/kg, and was made from 500.0 mL of water, how many grams of CaCl2 were needed to make the solution?
Step by step would be appreciated!
DrBob222, do you know how to do this?
The density of H2O=1g/mL, solve for mass.
mass=density*volume=(1g/mL)*(500mL)=500g or 0.500 kg
m=moles of solute/kg of solvent, solve for moles
(0.100 mol/kg)*(0.500 kg)= moles of CaCl2
moles of CaCl2*(111.0g/mole)= mass of CaCl2
****I'm not Dr. Bob222, but I think this is correct.
I'll buy all of that. Something like 5.55 g if I punched in the right numbers