Question
0.959 g of a hydrocarbon is dissolved in 10.00g of benzene. The freezing point of the solution is 1.16C. Find the molecular mass of the hydrocarbon. Benzene has a Kf of 5.12 and a freezing points of 5.53 degrees C.
Not sure how to go about solving this problem? Thanks!
Not sure how to go about solving this problem? Thanks!
Answers
DrBob222
Use the freezing point depression formula.
dT = Kf*m
Substitute and solve for m = molality.
m = mols/kg solvent.
Substitute and solve for mols.
mols = grams/molar mass
You know mols and grams, solve for mola rmass.
dT = Kf*m
Substitute and solve for m = molality.
m = mols/kg solvent.
Substitute and solve for mols.
mols = grams/molar mass
You know mols and grams, solve for mola rmass.