What is the molality of 151 grams of na2so4 dissolved in 547 g of water?

Molar mass Na2SO4 = > 142.04 g/mol

Number of moles:

n = sample mass / molar mass

n = 151 / 142.04 = > 1.063 moles

Mass of solvent in kilograms:

1 kg = 1000 g

574 g / 1000 = 0.574 kg

Therefore:

b = n solute / m solvent

b = 1.063 / 0.547

b = 1.943 mol/kg