Molality is a unit of measurement for concentration that is calculated through the equation,
m = moles of solute / kg of solvent
Recall that because water's density is approximately equal to 1 g/mL, 250 mL of water is also equal to 250 g or 0.25 kg. Substituting the known values,
0.6 = moles of solute / 0.25 kg solvent
moles of solute = 0.15 moles
Then, we determine the mass of sucrose by multiplying the calculated number of moles with the molar mass of sucrose (342 g/mol). The answer would be equal to 51.3 g.
