Question
How much ethyl alcohol, C2H5OH must be added to 500mL of water so that the solution will freeze at -10C? KfH2O = 1.86 C/molal
Answers
DrBob222
delta T = K*m
substitute and solve for m
m = mols/kg solvent. You have kg solvent (500 mL = 500 g if density is 1.0 g/mL, and 500 g = 0.500 kg.) and m, solve for mols solute.
Then mols solute = grams/molar mass. You have molar mass and mols, solve for grams C2H5OH.
substitute and solve for m
m = mols/kg solvent. You have kg solvent (500 mL = 500 g if density is 1.0 g/mL, and 500 g = 0.500 kg.) and m, solve for mols solute.
Then mols solute = grams/molar mass. You have molar mass and mols, solve for grams C2H5OH.