What is the mole fraction of LiCl in solution that is 9.0% by mass LiCl and has a density of 1.00 g/mL?
A)0.960
B)2.33
C)0.0403
D)2.12
E)9.00

Question

Quizplus · Accepted Answer

To find the mole fraction of LiCl, we need to first find the moles of LiCl present in the solution. We can do this by assuming we have 100 g of the solution and then calculating the mass of LiCl present in it:

Mass of LiCl = 9.0 g (given as 9.0% by mass)
Mass of solvent (water) = 91.0 g (100 g - 9.0 g)

Now, we can convert the mass of LiCl to moles:

Moles of LiCl = 9.0 g / 42.39 g/mol (molar mass of LiCl) = 0.2125 mol

Next, we need to find the moles of the solvent (water). We can do this by dividing the mass of the solvent by its density:

Volume of solvent = Mass of solvent / Density = 91.0 mL

Moles of H2O = Volume of solvent / molar volume of water
= 91.0 mL / 18.015 g/mol
= 5.051 mol

Finally, we can find the mole fraction of LiCl:

Mole fraction of LiCl = Moles of LiCl / Total moles
= 0.2125 mol / (0.2125 mol + 5.051 mol)
= 0.0403

Thus, the mole fraction of LiCl in the given solution is 0.0403 or 4.03%. Therefore, the correct answer is C.

What Is the Mole Fraction of LiCl in Solution That