In the absence of turbulent mixing, the partial pressure of each constituent of air would fall off with height above sea level in Earth's atmosphere as Pi=P(adsbygoogle = window.adsbygoogle || []).push({}); _{0i}e^{−Migz/RT}where Pi is the partial pressure at the height z, P_{0i}is the partial pressure of component i at sea level, g is the acceleration of gravity, R is the gas constant, T is the absolute temperature, and M_{i}is the molecular mass of the gas. As a result of turbulent mixing, the composition of Earth's atmosphere is constant below an altitude of 100 km, but the total pressure decreases with altitude as P=P_{0}e^{−Mavegz/RT}where M_{ave}is the mean molecular weight of air. At sea level, x_{N2}= 0.78084 and x_{He}= 0.00000524 and T= 300. K.

Im not really sure where to start with this. I figured maybe just start with the exponent of e and im confused right off the bat. using the info give it would be e^(28.9 g mol^{-1})(9.81m s^{-2})(6500m)/(300k)(R).....so im not sure what R to use, also i sort of remember something about e not being able to be raised to something with units and i end up with all kinds of units left all over the place?

**Physics Forums - The Fusion of Science and Community**

# Help me with this physchem problem about atmospheric pressure, please

Know someone interested in this topic? Share a link to this question via email,
Google+,
Twitter, or
Facebook

Have something to add?

- Similar discussions for: Help me with this physchem problem about atmospheric pressure, please

Loading...

**Physics Forums - The Fusion of Science and Community**