Answer:
Molality is 97.6 m (<u>option e</u>)
Explanation:
Density relates mass/volume. It is a data which is involved always to solutions, not solute, neither solvent.
0.858 g/mL = solution mass / 1000mL
0.858 g/mL .1000 mL = 858 grams of solution
Mole of solute = 20.3
Molar weight methanol = 32.04 g/m
Mass of methanol, in solution = molar weight . mol
32.04 g/m . 20.3 = 650.4 g
Mass of solution = Mass of solvent + Mass of solute
858 g = Mass of solvent + 650.4g
Mass of solvent = 858 g - 650.4 g → 207.6 g
So 20.3 moles of solute are contained in 207.6 g of solvent.
Molality is moles of solute/kg of solvent
20.3 m / 0.2076 kg = 97.6 m
