Q$13.$ When $0\mathrm{.}534g$ of a nonelectrolyte solute is dissolved in

$15g$ of water and the freezing point of water is reduced

from $0C$ to $-1\mathrm{.}57C.$ The freezing$-$point depression

constant for water is $1\mathrm{.}85Ck\frac{g}{m}ol.$ What is the molar

mass of the solute in this solution?