We’re being asked to **determine the mole fraction of CH _{3}OH** in

Recall that ** molality** is the ratio of the moles of solute and the mass of solvent (in kilograms).

In other words:

$\overline{){\mathbf{Molality}}{\mathbf{}}{\mathbf{\left(}}{\mathbf{m}}{\mathbf{\right)}}{\mathbf{=}}\frac{\mathbf{moles}\mathbf{}\mathbf{solute}}{\mathbf{kg}\mathbf{}\mathbf{solvent}}}$

**Mole Fraction (X)** relates the moles of solute and solvent within a solution:

$\overline{){\mathit{m}}{\mathit{o}}{\mathit{l}}{\mathit{e}}{\mathbf{}}{\mathit{f}}{\mathit{r}}{\mathit{a}}{\mathit{c}}{\mathit{t}}{\mathit{i}}{\mathit{o}}{\mathit{n}}{\mathbf{}}{\mathbf{\left(}}{\mathit{X}}{\mathbf{\right)}}{\mathbf{=}}\frac{\mathbf{m}\mathbf{o}\mathbf{l}\mathbf{e}\mathbf{}\mathbf{o}\mathbf{f}\mathbf{}\mathbf{s}\mathbf{o}\mathbf{l}\mathbf{u}\mathbf{t}\mathbf{e}}{\mathbf{m}\mathbf{o}\mathbf{l}\mathbf{e}\mathbf{}\mathbf{o}\mathbf{f}\mathbf{}\mathbf{s}\mathbf{o}\mathbf{l}\mathbf{u}\mathbf{t}\mathbf{i}\mathbf{o}\mathbf{n}}}$

**We’ll calculate the mole fraction of caffeine using the following steps:**

What is the mole fraction of CH_{3}OH in an aqueous solution that is 12.0 m in CH_{3}OH?

A. 0.333

B. 0.667

C. 0.178

D. 0.216

E. 0.400

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Mole Fraction concept. You can view video lessons to learn Mole Fraction. Or if you need more Mole Fraction practice, you can also practice Mole Fraction practice problems.

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Based on our data, we think this problem is relevant for Professor Shepler's class at GT.