Boiling point of a solution containing 1.28gram of naphthalene in 100gram  $CC{\mathcal{l}}_4$  is 350.5K. An unknown compound of mass 2.16grams in 200gram  $CC{\mathcal{l}}_4$  yields a solution with boiling point of 350.6K. If the molar mass of unknown compound is  $xgmo{l}^{-1}$, then the value of $\frac{x}{10}$    is (Boiling point of  $CC{\mathcal{l}}_4$  is 350 K)