home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Turnbull China Bikeride
/
Turnbull China Bikeride - Disc 2.iso
/
AVOGADRO
/
CHEMISTRY
/
UNITCONV
/
!UnitConv
/
MfpHelp
< prev
next >
Wrap
Text File
|
1996-04-14
|
3KB
|
94 lines
Information is available on:
Gases
Some Useful Data
________________________________________________
Note that if any read me files are
supplied as part of this application,
they may have more recent information
than is contained in this file.
UnitConv is © Chris Johnson, 1992
________________________________________________
This application provides interactive help when
the !Help application is active.
There are also other help displays with
appropriate information available from all other
menus associated with this application.
________________________________________________
Gases
You may enter values for the temperature of the
gas, the pressure of the gas, the size of the
molecule, and the relative molar mass into the
appropriate icons and then click on CALCULATE.
Pressing <RETURN> will be the same as clicking
CALCULATE. Use <TAB> or the up/down arrow keys to
move to each writable icon in turn.
If you have entered values for all four
parameters, then the following values will be
calculated.
Mean free path of the molecules.
RMS, average and most probable
velocities.
Collision frequency and the total
number of collisions in a cubic metre.
The program tries to be intelligent about what to
calculate. For example, the velocities require
only the temperature and the molar mass, whereas
the mean free path calculation requires
temperature, pressure and size of molecule. The
program calculates what it can, and leaves the
data fields blank if there is insufficient input
data for that calculation. If a temperature is not
entered, then an error message is generated.
Clicking MENU in this window allows you to change
the default units used for pressure (atmosphere,
N/m² and torr) and size (pm, nm and m), and to
enter the size either as the diameter or cross
sectional area. If you choose to enter the size as
a diameter, the program assumes the molecule is
spherical.
Remember - we are dealing with the COLLISION
cross-section. This is effectively PI x diameter²,
since the distance between centres of colliding
molecules is 2 x radius.
Temperature is always entered as kelvin.
The window remains on-screen until explicitly
closed.
________________________________________________
Some Useful Data
Collision cross-sections/(nm)²
He 0.21
Ne 0.24
Ar 0.36
H2 0.27
N2 0.43
O2 0.40
Cl2 0.93
CO2 0.52
SO2 0.58
CH4 0.46
C2H4 0.64
C6H6 0.88
________________________________________________