Pure Benzophenone Freezes At 48.1

Calculation of Benzofenone KF? 3

Question about one of my labs:

Pure benzophenone was frozen at 48.1 C. In addition to 1.25 g of phenyl (Mرller C12H10 = 154.2 g / mol), 25.38 g of benzophenone was frozen at 16.8 C. Calculate the Kf of Benzofenone.

I'm not sure I can, please help us! Steps are going to be great! Thank you very much! :)

Frozen Point Depression = molality x Kf

1.25 grams / 154.2 grams / mol = 0.008106 mol

0.008106 mol / 0.02538 kg = 0.3194 m

(48.1 16.8) = mKf = 0.3194 Kf

Kf = 98 degrees ° C / m