I have a couple electrochemical cells I will need to sparge (deaerate) with nitrogen prior to and possibly during my experiment (the solution is .1 M NaOH). Does this need to be done in a fume hood?

From what I've read, it seems that $\ce{N2}$ gas isn't a huge danger, but if you're in a confined space it can cause a severe lack of oxygen. If that is the case, would a normal-sized classroom count as a confined space? Also, from what I understand about deaeration, the nitrogen bubbles escape the solution with impurities, but also with oxygen, so maybe in my case the lack of oxygen wouldn't be a problem.

This may be a simple question, but it has been difficult for me to find standard procedures for sparging a liquid with an inert gas, and I want to make sure I'm taken all the necessary precautions and steps.

  • $\begingroup$ You're just using a stream of nitrogen. You can't have such a high flow that it will blow the liquid out of your container. As such, the risk of asphyxiation is quite low. On the other hand, if you work with a relatively dangerous liquid (your base is pretty dilute), you are at risk of blowing it out of the container and onto you, so you should do this in a fume hood with appropriate protective clothing and goggles. $\endgroup$ – Zhe Aug 8 '17 at 22:13
  • 1
    $\begingroup$ Adding some nitrogen to the atmosphere (already 70% nitrogen) is not a big deal. $\endgroup$ – Zhe Aug 8 '17 at 22:14
  • $\begingroup$ Not to count that if you deairate, you release air $\endgroup$ – Alchimista Aug 9 '17 at 23:00

As implied in the comments, you have nothing to fear by sparging your solution with nitrogen in the classroom. Even a good size tank only contains a few cubic meters of compressed gas, while your classroom likely contains a few hundred cubic meters of air. Thus, even if you could instantly empty the tank the effect would be negligible. And you will be using low enough flow rates that there will be no fear of a "localized" depletion of oxygen.

The safety issue that I need to mention, though you are almost certainly already aware, is regarding the sodium hydroxide solution. Even at $\pu{0.1 M}$ it's not something that you want in anyone's eyes, so protection against splatter from the sparging solution would be prudent.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.