Density of one molar solution is 0.54 g/cc. Molality of the same solution is ( GMW of solute = 40 g )

$$\begin{gathered} 1 \mathrm{M} \mathrm{solution} \mathrm{means} 1 \mathrm{mole}\left(40\mathrm{g}\right) \mathrm{solute} \mathrm{in} 1000 \mathrm{ml} \mathrm{of} \mathrm{solution} ; \\ {\mathrm{W}}_{\mathrm{solute}}=40 \mathrm{g}; \\ \mathrm{GMW} \mathrm{of} \mathrm{solute}=40 \mathrm{g}; \\ {\mathrm{V}}_{\mathrm{solution}}=1000 \mathrm{ml} ; \\ {\mathrm{W}}_{\mathrm{solution}}=\mathrm{V}\times \mathrm{d} ; \\ {\mathrm{W}}_{\mathrm{solution}}=1000 \mathrm{ml}\times 0.54 \mathrm{g}/\mathrm{ml} ; \\ {\mathrm{W}}_{\mathrm{solvent} }=\left(540-40\right) \mathrm{g} \\ \mathrm{m}=\frac{40}{40}\times \frac{1000}{500}=2 \mathrm{m} ; \end{gathered}$$