|MadSci Network: Chemistry|
Gas Effusion Theory doesn't apply here, because of various conditions,
especially because it is a very simplified concept of what is actually taking
place, and for this to actually happen, the container cannot be pressurized.
The best way to actually approach this problem would be to use thermodynamics and assuming you know the area of the pinhole, the temperatures inside and out, the pressure inside and out, you could assume ideal gas, except that the gas compresses (different density) and you could assume that there exists no temperature drop due to leaking gas (which actually happens (but the effect due to this on time would be negligible)
Hope this helps, but just a reminder again, this forum just answers your questions for information, and is not a forum for technical answers. Please seek a professional's help if this is for research.
Try the links in the MadSci Library for more information on Chemistry.