Sciencemadness Discussion Board

Pressure inside a heated, closed bottle

nandrol - 4-1-2013 at 14:24

Can someone help me a bit.

Let's say I've got 3, 500ml glass bottles filled to 1/4th, half and 3/4th of their volume respectively with 25% ammonium hydroxide. How can I estimate what will be their internal pressure?


EDIT: I'm sorry but I wrote it all wrong. I forgot that the bottles were suppose to be heated. The question was aboutl pressure in heated closed bottles. What would be their internal pressure at 20 C, 100 C and 160 C. It's all theoretical, I don't want to experiment with exploding bottles.

Thanks for replies guys!

[Edited on 5-1-2013 by nandrol]

Siggebo - 4-1-2013 at 14:27

The pressures in the three bottles will be the same.

Current air pressure + vapor pressure of ammonia.

Edit: Wait, didn't think before I posted. Disregard second statement; it applies to an ideal system only.
The necessary data can be found at http://en.wikipedia.org/wiki/Ammonia_%28data_page%29#Vapor-L.... The calculation is analogous.

[Edited on 2013-1-4 by Siggebo]

[Edited on 2013-1-4 by Siggebo]

[Edited on 2013-1-4 by Siggebo]

AndersHoveland - 5-1-2013 at 00:03

On a somewhat related topic, a plastic soda bottle can hold between 3 to 5 atmospheres of pressure.

nandrol - 5-1-2013 at 04:07

I'm trying to count it but I'm not sure how to.

I assume I should first calculate the vapor pressure of ammonia, water and air using the Antoine Equation:

http://www.ehow.com/how_4479034_calculate-vapor-pressure.htm...

What next?

Should I count the mole fraction and multiply that by the vapor pressure like here:

http://www.ehow.com/how_6201518_calculate-vapor-pressure-sol...

or should I calculate each components mass fraction and multiply by vapor pressure:

http://www.ehow.com/how_12028243_calculate-vapor-pressure-pr...

[Edited on 5-1-2013 by nandrol]

[Edited on 5-1-2013 by nandrol]