We’re being asked to calculate for the molar mass at 97°C and 0.958 atm.

To calculate for the molar mass, we’re going to use the **ideal gas equation**.

$\overline{){\mathbf{P}}{\mathbf{V}}{\mathbf{=}}{\mathbf{n}}{\mathbf{R}}{\mathbf{T}}}\phantom{\rule{0ex}{0ex}}\frac{\mathbf{P}\overline{)\mathbf{V}}}{\overline{)\mathbf{V}}}\mathbf{=}\frac{\mathbf{n}\mathbf{R}\mathbf{T}}{\mathbf{V}}\phantom{\rule{0ex}{0ex}}\mathit{P}\mathbf{=}\frac{{\mathbf{n}}\mathbf{R}\mathbf{T}}{\mathbf{V}}$

${\mathit{n}}{\mathbf{=}}\frac{\mathbf{m}\mathbf{a}\mathbf{s}\mathbf{s}\mathbf{}\left(\mathbf{m}\right)}{\mathbf{m}\mathbf{o}\mathbf{l}\mathbf{a}\mathbf{r}\mathbf{}\mathbf{m}\mathbf{a}\mathbf{s}\mathbf{s}\mathbf{}\left(\mathbf{M}\right)}$

A chemist vaporized a liquid compound to determine its molar mass. If the density of the vaporized liquid (collected in a 120 mL flask) at 97°C is 3.24 g/L, and the pressure exerted by the vaporized liquid is 0.958 atm, what is its molar mass?

(a) 103 g/mol

(b) 121 g/mol

(c) 187 g/mol

(d) 31.6 g/mol

(e) Insufficient information was given to calculate molar mass.

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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 Ideal Gas Law Density concept. If you need more Ideal Gas Law Density practice, you can also practice Ideal Gas Law Density practice problems.