At 04:10 PM 1/27/2003 -0800, Randall Clague wrote:

That's odd.  1.9 was only a BOTE, but I was expecting better accuracy
than 5%.  I used:

N atomic weight: 14
O atomic weight: 16
H2 molecular weight: 2
ICAO sea level density of air: 1.225 kg/m^3
liters per mole at STP: 22.4

to get

air atomic weight: 14.4
H2 molar weight: 3.8 grams

then realized I use atomic weights for N and O and molecular weight
for H2.  Correction yields 1.9 g/mol.

Oh bother.  14.4 is 20% N 80% O.  With 15.6 I get...2.06 g/mol.  Still
a 3% error.

What am I doing wrong?

At a glance, you left out the contributions of Ar, CO2, and water vapor. That and the fact that you rounded off the molar weights of O2 and N2 should be enough to make up your 3% error.

-p



Mars or Bust!
www.marssociety.com

_______________________________________________
ERPS-list mailing list
[EMAIL PROTECTED]
http://lists.erps.org/mailman/listinfo/erps-list

Reply via email to