Help finding energy required for endothermic reaction(s)

[tuprox]

I'm working on a strange theory and I need a little help on this as I'm not very good with chemistry and physics. I apologize if this is not in the correct forum, if it isn't please move it to where it should go.

 

Ok, Here is the data that I have:

 

Liquid nitrogen density is .807g/ml @ temps of -320.44 and -195.8C :-: 1KG = 1,239.2ml

Liquid Oxygen density is 1.141g/ml @ -297.33F and -182.96C :-: 1KG = 876.5ml

 

I am wondering what the effect would be if 1KG of one of these liquids were sprayed into a room that is 10'x10'x10' so 1,000 cubic feet. Let's say that the room temperature is 72F degrees. (or would it be easier to use 1L of the substance?)

 

What could be the expected temperature in the room after spraying one of the liquids. Could you show me how you do it? Also, how many BTU's, joules or KW's would this be?

 

Is there anything that I am missing here that I should ask or think of? This could be pretty interesting depending upon the results.

 

Also, does anyone know how fast a liquid spray would disperse if sprayed into a room such as this - would it evaporate it pretty quickly?

 

Am I asking the correct questions?

 

Anyone else find this interesting?

Edited October 30, 2012 by tuprox

[Enthalpy]

You don't have to theorize it because many people have done it, especially for fun. Spectacular, but little happens with nitrogen.

 

The heat source for evaporation is not the atmosphere but the much bulkier ground. It evaporates nitrogen in few seconds or less if you disperse it properly.

 

27m³ air in the room weigh already 30kg of which 25kg are nitrogen so 1kg nitrogen isn't a radical change. The resulting mix after some time, as evaporated nitrogen would cease to pick heat from the ground as a gas at -196°C, would be some 6K colder than initially. After much longer, the walls will bring the air back to temperature.

 

The overpressure would correspond to 1/30 more moles but brought in at 1/4 of 300K, so about 1/120 more pressure or 8mb, climbing to 1/30, hours after. If the room were completely hermetic, you would feel it in the ears. I suppose the walls and windows resist, but I'd open a window in advance.

 

I strongly recommend NOT to do it with liquid oxygen. This is a seriously dangerous stuff.

[tuprox]

You don't have to theorize it because many people have done it, especially for fun. Spectacular, but little happens with nitrogen.

 

The heat source for evaporation is not the atmosphere but the much bulkier ground. It evaporates nitrogen in few seconds or less if you disperse it properly.

 

27m³ air in the room weigh already 30kg of which 25kg are nitrogen so 1kg nitrogen isn't a radical change. The resulting mix after some time, as evaporated nitrogen would cease to pick heat from the ground as a gas at -196°C, would be some 6K colder than initially. After much longer, the walls will bring the air back to temperature.

 

The overpressure would correspond to 1/30 more moles but brought in at 1/4 of 300K, so about 1/120 more pressure or 8mb, climbing to 1/30, hours after. If the room were completely hermetic, you would feel it in the ears. I suppose the walls and windows resist, but I'd open a window in advance.

 

I strongly recommend NOT to do it with liquid oxygen. This is a seriously dangerous stuff.

 

Thanks for the response and putting it in perspective. I was trying to do some calculations of what would happen if 10-20 loaded 747-400's were filled with liquid air (each able to dispense 99,582 litres of liquid air @ -319F flew into a hurricane and dispersed it's payload. Since the air is warmer and basically the "battery" (well the hot gulf stream or Caribbean is the real battery) this payload might dampen the strength of the storm.

 

What do you think of this theory or has it been tried?