A solution is prepared by dissolving 76.3 g NaI in 545 g of water. Determine the mole fraction of NaI if the final volume of the solution is 576 mL.

Mole fraction NaI → 0.016

Explanation:

Mass of solute: 76.3 g (NaI)

Mass of solvent: 545 g (H₂O)

Let's determine the moles of each:

Mol of solute → 76.3 g. 1 mol / 149.89 g = 0.509 moles

Mol of solvent → 545 g. 1mol / 18 g = 30.2 moles

To calculate the mole fraction → Moles of solute / Total moles

Total moles = 0.509 + 30.2 → 30.709

Mole fraction NaI = 0.509 / 30.709 = 0.016