FAQ - Gas Measurement Primer

[J16]

This basic guide to gas measurement and conversions should help reduce the numerous mistakes that people have been making. I will expound on this document is people find it useful. Finally all those hours of chemistry class are paying off.
Basic Gas Measurement Primer

1 Mole = 6.022 * 10^23 particles

Atomic weight = mass in grams of 1 mol of substance

STP = Standard Temperature and Pressure = 1 Atm @ 0 degrees Celsius

1Mol of gas@ STP has a volume of 22.4 Liters

Combined Gas Law
(P1V1)/T1 = (P2V2)/T2

1 is Original Value 2 is changed value
**Note these gas laws apply to ideal gases. At extreme pressures and/or tempuratures the variation may be significant.

Ideal Gas law PV = nRT

P = Pressure in kPa (Kilopascals)
V = Volume in L (Liters)
n = number of molecules in Moles
R = 8.3144 J mol-1K-1
T = Temperature in Kelvin

To convert from C to K just add 273
0 degrees kelvin = -273 Celsius

Volume Convertsion

1 psi 6.894757 kPa
1 Atm 101.325 kPa = 760 mmHg
1 bar 100 kPa
1 mm Hg 0.1333 kPa

1 mm Hg 1 torr
1 micron .001 torr

Hydrogen is diatomic hence it exists as H2

Atomic Weights
Oxygen = 16g
Deuterium = 2.01g
Hydrogen = 1.01

H2O = 18.02g
D2O = 20.02g

10g of D20 is composed of .499 Moles
Electrolyzed it yields .499 Moles of D2
At STP it has a volume of 11.2 Liters

[Richard Hull]

Thanks Joe!

I went in and used my universal editing powers to add "FAQ" to your title. This will allow a quick search on the most valuable, all inclusive expositions of data mining on a subject in any forum.

One thing that is most useful is the number of molecules per cc at fusor pressures. (10u)

At STP a cubic centimeter would contain 6.02 X10e 23 / 22.4X10e3= 2.69 X 10e19 molecules

At 10 microns, there would be 2.69X10e19 X 1.3X10e-5 = ~3.5X10e14 molecules of gas/cc in in our fusors. One would have to double this to arrive at number of deuterium atoms. (diatomic molecules)... So, at standard temps but at fusion pressures there are 7X10e14 or 700 trillion atoms of deuterium in every cc of fusor volume.

A 6" fusor would have a radius of 7.62 cm and therefore a volume of 1852 cc. In round numbers, a fusor might have a total of 1.3X10e18 atoms of deuterium in it at operating pressure. Only an unbelievably tiny fraction of these are involved in fusion. ~ 1million/sec. One atom in every trllion is about right. For every atom that fuses each second there are another 999,999,999,999 atoms which are just movin' around doing nothing,

Regarding the D2 issue...... 100 grams of D2O would contain ~111 liters of D2 at STP. The cost of this much D2O is ~ $60.00 delivered. This rates as only being about 1/4 as expensive as bottled D2 gas. This is why the electrolytic D2 generator appears so attractive to so many inspite of the extra hassles associated with the assembly of the system.

Richard Hull