Haloalkanes And Haloarenes

RMgI when treated with ice cold water liberated a gas which occupied $1.4 \mathrm{dm}^3 / \mathrm{g}$ at STP. The gas produced is further reacted with iodine in presence of $\mathrm{HIO}_3$ to give compound $(\mathrm{X})$. Compound $(\mathrm{X})$ in presence of Na and dry ether produced compound $(\mathrm{Y})$. Molar mass of compound $(\mathrm{Y})$ is $\_\_\_\_$ $\mathrm{g} \mathrm{mol}^{-1}$. (Nearest integer)