[Robbie91]

Ok, this question has been stumping me a bit:

An oxygen cylinder has a volume of 50 liters and a pressure of 200 atmospheres.  If the cylinder is used to supply oxygen to a patient at a flow of two liter/minute (at 1 atm pressure), how long will the tank last?

Disregarding the gas laws in my book for now (since none seemed to apply---nor could I find a comparable problem), I multiplied 50 by 200 to get 10,000 and then divided by 2 for the liters/min and I got 5000 minutes, 5000/60 is 83.3 hours.

If this is wrong , could someone point me in the right direction as to which gas law I should be looking at to figure this out.  Thanks.

[Borek]

It's OK.

You will get exactly the same result using pV = const (or p₁V₁ = p₂V₂) - which is one the gas laws you have just disregarded.

[Donaldson Tan]

i would like to add: assuming isothermal condition

ps: this is my 1234th post. i wonder when i will reach 12345. LOL! finally back from my european trip. it has been a wonderful time.