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. A) 6.04 × 10^-3 B) 1.65 × 10^-2 C) 1.40 × 10^-³ D) 1.32 × 10^-2 E) 8.84 × 10^-2

Question

Quizplus · Accepted Answer

First, we need to calculate the moles of NaI in the solution:

Moles of NaI = mass / molar mass = 76.3 g / 149.89 g/mol = 0.509 mol

Next, we need to calculate the moles of water in the solution:

Moles of water = mass / molar mass = 545 g / 18.015 g/mol = 30.248 mol

The total moles of solute and solvent in the solution are:

Total moles = moles of NaI + moles of water = 0.509 mol + 30.248 mol = 30.757 mol

Finally, we can calculate the mole fraction of NaI:

Mole fraction of NaI = moles of NaI / total moles = 0.509 mol / 30.757 mol = 0.0165

This can also be expressed in scientific notation as 1.65 × 10^-2. Therefore, the best answer choice is B.

A Solution Is Prepared by Dissolving 76