Concentration terms

1.00 m means 1 mol solute in 1000 g water.
$n_{H_2O} = \frac{1000}{18} = 55.5$ mol
$X_{solute} = \frac{1}{1 + 55.5} = 0.0177$

A 1.00 molal aqueous solution contains 1 mole of solute in 1000 g of water.
Moles of water = $\frac{1000}{18} = 55.55$
Mole fraction of solute = $\frac{n_{solute}}{n_{solute} + n_{water}}$
$= \frac{1}{1 + 55.55} = \frac{1}{56.55}$
= 0.0177