- #1

- 3

- 0

When I say liquefied air, I mean regular earth atmospheric air that has been super cooled and condensed to a liquid. I know that the earths atmosphere is 78% Nitrogen, 21% Oxygen, and for this experiment I am to assume 1% water vapor (H2O). The consistencies do not change from the gas to liquefied form or liquefied form to gas in my thought experiment. The percentages always stay the same and do not change.

Upon cooling Oxygen would liquefy before Nitrogen at -297 degrees F, or -183 degrees C (90.2 K).

Then upon more cooling Nitrogen would then liquefy at -320 degrees F, or -196 degrees C (77.36 K).

I am to assume that the temperature of my liquefied air is starting at 77.36 Kelvin so that the entire substance is in liquid form at the start of the thought experiment.

I was not given any pressure it is under, I only know that it is liquefied air I am starting with but it is at sea level, so I am assuming the liquefied air is starting and ending at the same pressure, which is 1 bar. I was not given a volume that it is currently residing in. I only know that the mass of this liquefied air is .0417 grams at the start before it expands.

I have researched and found out that liquefied air has a density of 870 kg/m3 (0.87 g/cm3), but I am not sure what temperature this information was cited at. This could be where my equations went wrong. Is liquefied air really this dense or am I incorrect?

I have also researched and found out that regular air has a density of 1.204 kg/m3 (.001204 g/cm3) at 1atm (sea level) or also known as 1 bar and 20 degrees Celsius. Therefore, liquefied air would seem to be 722.59 times more dense than regular atmospheric air at 20 degrees Celsius and at 1 bar according to this information if it is correct. I just need to make sure that I have the density of liquefied air correct. I may have it wrong.

I have found out that Volume = Mass/Density. I did the calculation and found that liquefied air with a density of 870 kg/m3 (0.87 g/cm3), and a mass of .0417 grams, would have a volume of 47.931 Cubic Millimeters or 0.047931 Cubic Centimeters (cc).

Regular air at 1 bar and 20 degrees Celsius with a density of 1.204 kg/m3 (.001204 g/cm3) and also a mass of .0417 grams would have a volume of 34,635 Cubic Millimeters or 34.635 Cubic Centimeters (cc). Therefore, liquefied air would seem to expand 722.601 times when heated to 20 degrees Celsius. I just need to make sure that I have the density of liquefied air correct.

Since the liquefied air is starting out at -196 degrees Celsius, and is introduced to room temperature, which is to be 20 degrees Celsius for this experiment, the temperature change is immediately a 216 degee change.

Are my calculatiosn correct? Would liquefied air expand over 722 times if you raised the temperature by 216 degrees instantly? Or are my calculations wrong somewhere? I really need someone to find out the density of liquefied air at -196 degrees Celsius (77.36). If I have the density wrong my calculations would be all wrong.

The consistency does not change, the percentages of the mixtures in the air stays the same, only the temperature changes.

If someone could help it would be much appreciated because I have been attempting to figure this out for quite some time.