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.
To determine the mole fraction of NaI in the solution, we first need to calculate the moles of NaI and water.
The moles of NaI can be calculated using its molar mass, which is 149.89 g/mol.
moles of NaI = mass of NaI / molar mass of NaI
moles of NaI = 76.3 g / 149.89 g/mol
moles of NaI ≈ 0.509 mol NaI
The moles of water can be calculated using its molar mass, which is 18.02 g/mol.
moles of water = mass of water / molar mass of water
moles of water = 545 g / 18.02 g/mol
moles of water ≈ 30.24 mol water
Next, we calculate the total moles in the solution.
total moles = moles of NaI + moles of water
total moles ≈ 0.509 mol NaI + 30.24 mol water
total moles ≈ 30.75 mol
Finally, we calculate the mole fraction of NaI.
mole fraction of NaI = moles of NaI / total moles
mole fraction of NaI = 0.509 mol NaI / 30.75 mol
mole fraction of NaI ≈ 0.0166
Therefore, the mole fraction of NaI in the solution is approximately 0.0166.