[bowersst]

I am unsure which equation to use in this problem:

At an altitude of 60.00 km, the average atmospheric temperature is essentially 0 degrees C. What is the average number of air molecules per cubic centimeter of air at this altitude?

^I was thinking that I could just solve the equation for the pressure as a function of height and temperature and from this use the ideal gas equation to calculate the volume of air. My dilemna is that I cannot find the equation for pressure as a function of height. Am I supposed to get this from a table or something?

[Demotivator]

Well there are tables.

There is also a hydrostatic equation
dp/dz = -dens(g)
dens is average density of air at sea level. (it happens to be about 1.3 kg/m3 at normal temp)
g is gravitational acceleration (9.8 m/sec^2)

The way I see it,
dens can be calculated from n/V = P/RT
where P is about 1 atm at sea level and T = 273K (0 C). (Although temp really isn't on average zero C at the surface, setting it at 0C now makes it unnecessary to readjust P for 0 C at altitude.)
n/V is related to density through a costant (weighted average MW of air).

The equation can be integrated to solve for P at a delta z.
Of course, you have to be careful with the units.

[bowersst]

Thank you for the reply.

I have looked in my chem and physics books, but have found no tables. If you know of a table of this sort available online, let me know. In the meanwhile, I will try and calc it.

[Demotivator]

http://www.sablesys.com/baro-altitude.html

btw,  60.0 km?  seems too high a number to me.

[billnotgatez]

Let us know if the density is near 0.0003 kg/m3