Answer
0.881 m
Work Step by Step
Molality= $\frac{\text{Moles of solute}}{\text{Mass of solvent in kg}}$
Moles of glucose= $257\,g\times\frac{1\,mol\,glucose}{180.156\,g}=1.42654\,mol$
Mass of water in kg= $\frac{1.00\,g}{1\,mL}\times\frac{1\,kg}{10^{3}\,g}\times\frac{1\,mL}{10^{-3}\,L}\times1.62\,L=1.62\,kg$
Then, molality=$\frac{1.42654\,mol}{1.62\,kg}=0.881\,mol/kg=0.881\,m$