Question

John dissolves .5g of a white powder in 25g of benzene (FP 5oC) (kf benzene is 5.1) and finds the solution freezes at 3.7oC. Determine the MW of the compound!

Answer 1

let the molar weight of the compound be $M$.

now, $1.3=5.1\times\frac{\frac{5}{M}}{25\times10^{-3}}$

$M=784.615\frac{g}{mol}$