I need to presurise a vessel to 3bar with helium but do not know how much gas to order
2006-07-02 23:04:30 · 10 answers · asked by iandixon_99 1 in Science & Mathematics ➔ Physics
One of the following:
PV=nRT
P1V1=P2V2
P1/T1=P2/T2
2006-07-02 23:08:36 · answer #1 · answered by Scozbo 5 · 0⤊ 0⤋
Industrial gases are sold by the cubic foot; the standard steel cylinder holds 220 cubic feet at a pressure of about 2200 psi (about 150 bar). Measure the volume of your vessel (e.g., fill it with water), and since you want 3 bar pressure, triple that, and that'll tell you how many cubic feet you need. Gotcha: if your vessel is filled with air to start with, and you don't want air mixed with the helium, you will need to collapse the vessel or pump the air out with a vacuum pump before inserting the helium.
-- Robert A. Saunders, Lake Stevens, WA.
2006-07-02 23:16:20 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The volume of any gas is always inversely equivalent to the ammount of pressure that is exercised on the gas as long as the temprature remains constant - Boyle's law
After you used this law use the formula pV = nRT
p=pressure in kPa
V= Volume in m^3
n = mole
R = 8.31(There was a name for this constant, but I can't remember it)
T = temprature in K
You want to solve for n
After you solved for n multiply it with the relative atom/molecule mass and then you will have the amount of mass of the gas you need in grams
OR you could multiply n with 22.4 dm^3 and will have the volume of gas you need in cubic decimetres
Sorry for the bad translation, but english is'nt my mother's tongue
I'm still trying to figure out why there is no yahoo.co.za
2006-07-04 09:29:30 · answer #3 · answered by nobody 2 · 0⤊ 0⤋
i would say that thejur has the best answer so far however his calculation would have and insagnifigant inacuract as the universal gas constant
no.1 is different depending on the gas (it is only of that set value for an ideal gas which does not exist)
no.2 the gas constant changes with temperature
2006-07-04 07:27:01 · answer #4 · answered by kevin h 3 · 0⤊ 0⤋
pV=nRT pressure x volume = molars of gas x universal gas constant (8.75) xTemperature in Kelvin
2006-07-02 23:59:02 · answer #5 · answered by thejur 3 · 0⤊ 0⤋
sit on the loo after a curry,shut the doors and windows and you'll soon find out! BOOM!
2006-07-02 23:09:12 · answer #6 · answered by downingtesco 2 · 0⤊ 0⤋
pressure = force/area
2006-07-02 23:37:16 · answer #7 · answered by rosy babe 1 · 0⤊ 0⤋
dont order any just pucker your lips and blow you know how to whistle dont you
2006-07-09 23:09:28 · answer #8 · answered by cookedermott 6 · 0⤊ 0⤋
boyles law. look it up.
2006-07-02 23:54:21 · answer #9 · answered by jedi_reverend_daade_selei 3 · 0⤊ 0⤋
P*V=R*T
2006-07-02 23:12:50 · answer #10 · answered by IT 4 · 0⤊ 0⤋