How Many Air Molecules Were Released from the Compressed Tank?

AI Thread Summary
The discussion revolves around calculating the number of air molecules released from a compressed tank using the ideal gas law equations PV = NkT and PV = nRT. The user initially applied these equations to determine the number of molecules at two different pressures (50 atm and 17 atm) but arrived at an incorrect final count. A key point raised is the importance of checking units, particularly whether atmospheres can be used directly in the calculations. The user seeks clarification on the correct approach to solve the problem accurately. Proper unit conversion and application of the ideal gas law are essential for obtaining the correct answer.
underoathP
Messages
5
Reaction score
0
A tank of compressed air of volume 1.0 m^3 is pressurized to 50 atm at T = 273 K. A valve is opened and air is released until the pressure in the tank is 17 atm. How many air molecules were released?


I tried this problem using PV = NkT and PV = nRT. I realize the difference in these equations and I was wondering if this in fact the right equations to use? I ran 50 atm through and then 17 atm through. I then subtracted the initial N minus the final N. This didn't work.


This is what I did:

(50 atm)(1.0 m^3) = N(1.38e-23)(273)
N = 1.327e22

(17)(1.0 m^3) = N(1.38e-23)(273)
N = 4.512e21

Nfinal = (1.327e22) - (4.512e21)
Nfinal = 8.758e21

This is the wrong answer. What should I do?
 
Physics news on Phys.org
Check your units, can you really use atmospheres with that equation?
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...

Similar threads

Back
Top