Chemical to absorb oxygen and nitrogen

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Discussion Overview

The discussion revolves around the search for a chemical that can absorb oxygen and nitrogen in solid form, with the aim of creating a vacuum in a PVC pipe. Participants explore various methods and substances that could potentially achieve this goal, while also considering the implications of pressure on gas absorption.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about the possibility of using a chemical to absorb oxygen and nitrogen to create a vacuum in a PVC pipe.
  • Another participant argues that a reduction in pressure would hinder the absorption process, drawing a parallel to the effects of a vacuum on human physiology.
  • It is suggested that a solid substance could react with oxygen to form a stable compound, but this would also face challenges at low pressure.
  • A participant proposes using a conventional vacuum pump instead of chemicals for depressurizing the pipe.
  • Another participant mentions modifying a bicycle pump into a vacuum pump and discusses the need for a sealing mechanism after gas removal.
  • A participant introduces magnesium as a potential solid compound that reacts with nitrogen, referencing the formation of magnesium nitride and its reactions with other substances like CO2 and water vapor.
  • Concerns are raised about the possibility of residual nitrogen remaining even after using excess magnesium, along with warnings about the high temperatures and UV radiation produced during magnesium combustion.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of using chemicals to absorb gases versus employing a vacuum pump. There is no consensus on the best approach, and multiple competing ideas remain present in the discussion.

Contextual Notes

Participants highlight limitations related to pressure effects on gas absorption and the potential for residual gases remaining after chemical reactions. The discussion also touches on the safety concerns associated with high-temperature reactions.

cragar
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Is there a chemical that can absorb oxygen and nitrogen and in solid form.
I need to make a vacuum in a pvc pipe or close to a vacuum.
I was wondering if there were some chemicals that I could insert into the pipe and then close the end and tip it over and mix the chemicals together that would absorb the oxygen and nitrogen in the pipe and make it close to vacuum.
 
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One problem with that idea is that the reduction in pressure would oppose the absorption from taking place. Think about what happens to a human in a vacuum. All the gases in the lungs and blood stream get violently pulled out of the body, If you found a solid substance that absorbs these gases effectively, it wouldn't be able to retain the gases in low pressure environments. You could use a substance that reacts with the oxygen and form a highly stable solid complex with it but a similar problem exists, the lower the pressure, the lower the extent of reaction that can take place.

Why not just depressurise the pipe the conventional way, using a vacuum pump?
 
ok i see your point. Ill see if I can get a pump
 
With respect to the solid compound, a burning strip of Mg. Reaction with nitrogen, per Wikipedia (http://en.wikipedia.org/wiki/Magnesium_nitride )

"Magnesium nitride can be produced by heating magnesium metal in a pure nitrogen atmosphere.

3 Mg + N2 → Mg3N2

In fact, when magnesium is burned in air, some magnesium nitride is formed in addition to the principal product, magnesium oxide."

Note, per Wikipedia, some CO2 and water vapor can also be removed as well:

2 Mg + CO2 --> 2 MgO + C

Mg + H2O --> MgO + H2

[EDIT] I would also add CaCl2 as any moisture could react with the Mg3N2 to form NH3. Reaction:

Mg3N2 + 3 H2O --> 3 Mg(OH)2 (s) + 2 NH3 (g)

Ammonia reacts with CaCl2 as follows forming adducts:

CaCl2 + 4 NH3 --> CaCl2.xNH3 (where x=1, 2, 4 or 8)

and the CaCl2 will also absorb any water vapor.

I still suspect, however, there will be some N2 remaining even with excess Mg. Note also, burning Mg is very hot (3,100 C) and gives off strong uv radiation.
 
Last edited:

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