# Problem: The density of a gas is 1.42 g/L at a temperature of 23 oC and a pressure of 0.786 atm . Calculate the molar mass of the gas.

###### FREE Expert Solution

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

$\mathbit{P}\mathbf{=}\frac{{\mathbf{m}}\mathbf{R}\mathbf{T}}{\mathbf{M}{\mathbf{V}}}$

$\frac{\mathbf{m}}{\mathbf{V}}{\mathbf{=}}\frac{\mathbf{g}}{\mathbf{L}}{\mathbf{=}}{\mathbit{d}}{\mathbit{e}}{\mathbit{n}}{\mathbit{s}}{\mathbit{i}}{\mathbit{t}}{\mathbit{y}}\left(\mathbf{d}\right)$

$\mathbit{P}\left(\mathbf{M}\right)\mathbf{=}\frac{{\mathbf{d}}\mathbf{R}\mathbf{T}}{\overline{)\mathbf{M}}}\left(\overline{)\mathbf{M}}\right)\phantom{\rule{0ex}{0ex}}\frac{\mathbf{P}\mathbf{M}}{\mathbf{R}\mathbf{T}}\mathbf{=}\frac{\mathbf{d}\overline{)\mathbf{R}\mathbf{T}}}{\overline{)\mathbf{R}\mathbf{T}}}\phantom{\rule{0ex}{0ex}}\overline{){\mathbf{d}}{\mathbf{=}}\frac{\mathbf{P}\mathbf{M}}{\mathbf{R}\mathbf{T}}}$

Calculating the molar mass of the gas:

92% (150 ratings)
###### Problem Details

The density of a gas is 1.42 g/L at a temperature of 23 oC and a pressure of 0.786 atm . Calculate the molar mass of the gas.

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 The Ideal Gas Law: Density concept. You can view video lessons to learn The Ideal Gas Law: Density. Or if you need more The Ideal Gas Law: Density practice, you can also practice The Ideal Gas Law: Density practice problems.