Answer to Question #162187 in General Chemistry for Amy

Question

0.205 grams of molecular compound is dissolved in 110ml of pure distilled water at 25c. The solution freezes point temp is then experimentally measured to be -0.0956C. What is the molecular weight of a compound?

Answer 1

$\Delta Tf$ = Kf×m

$\Delta Tf$ = Kf × (w/m)×(1000/V)

-0.0956 = 1.86×(0.205/m)×(1000/110)

m = 32.25 g