Molality and mole fraction

Exercise 5

    

Which is the mole fraction of solvent in an aqueous $1,00\; m$ solution ?

$1000\;g$ water contain $0.1\;mole$ of solute $so$. $n_{H_2O}$ $=$ $\frac{m_{H_2O}}{M_{H_2O}}$ $=$ $55.5\;mol$ $X_{H_2O}$ $=$ $\frac{n_{H_2O}}{n_{H_2O}+n_{so}}$ $=$ $0.982$