What is the molality of a solution containing 13.4 g Na2SO4 dissolved in 1524.9 g of water?

Question

What is the molality of a solution containing 13.4 g Na₂SO₄ dissolved in 1524.9 g of water?

Answer 1

Molality = moles solute / kg solvent

Find the moles of Na2SO4 by dividing 13.4 g by the molar mass for Na2SO4

Divide those moles by 1.5249 kg

Correct for sig. figs. to get your answer in units of molal