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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: g00ber on November 08, 2004, 09:50:16 PM

Title: Gas Tank Problem
Post by: g00ber on November 08, 2004, 09:50:16 PM
A gas tank containing N2 has a volume of 25.0 L and a pressure of 35.0 atm.
A second tank, containing O2, has a volume of 10.0L and a pressure of 15.0 atm.
Both gases are pumped into a third tank with a volume of 15.0 L.


a) What is the partial pressure of each in the new tank?

b) What is the total pressure in the new tank?

Title: Re:Gas Tank Problem (Homework Help)
Post by: Mitch on November 08, 2004, 09:54:28 PM
You actually have to attempt the problem, and keep multiple questions in only one thread.
Title: Re:Gas Tank Problem (Homework Help)
Post by: cashsphere on November 08, 2004, 10:03:46 PM
This question is confusing is the N2+O2 equally distributed into tank 3?

For help look for Ideal Gas Laws and specifically Dalton's law of partial pressure
Title: Re:Gas Tank Problem (Homework Help)
Post by: AWK on November 09, 2004, 01:47:05 AM
Temperature is missing!

Treat both gases as ideal. Calculate moles of both gases. Pressure in the third tamk is proportional to sum of moles. partial pressue is proportional to mole fractions of both gases.
Title: Re:Gas Tank Problem (Homework Help)
Post by: Donaldson Tan on November 09, 2004, 08:06:04 AM
assumption:
1. all gases are at the same fixed temperature.
2. they exhibit ideal behavior.
3. no chemical reaction takes place

we can use the relation P indirectly proportional to V, ie. PV = constant.
This translates to P1V1 = P2V2

new volume of tank = V2 = 15.0L

considering nitrogen,
(35.0atm)(25.0L) = (P2)(15.0L)
partial pressure of nitrogen = P2 = (35.0atm)(25.0L) / (15.0L) =  58.3atm

considering oxygen,
(15.0atm)(10.0L) = (P2)(15.0L)
partial pressure of oxygen = P2 = (15.0atm)(10.0L) / (15.0L) =  10.0atm

total pressure in new tank = 10.0 + 58.3 = 68.3atm