[sethstacey]

Hello everyone,

I just found this forum. I have an idea for a demonstration of a sterling engine.

Here is the chemical part of it:

I want to somehow color the air so as to see it move around (the mechanism will be clear). I would love for it to color differently at a higher temperature than at a lower temperature.

Has anyone seen something that would do this?

Thanks for your help,
Seth

[nj_bartel]

 http://en.wikipedia.org/wiki/Dinitrogen_tetroxide

That's a seriously nasty compound though.

[sethstacey]

Wow--never would have thought of that. Very cool.

It would ideally be not something terribly toxic.

Thanks for the reply!

Seth

[Borek]

Sorry, as far as I know there are no safe, colored gases. This question pops now and again, you may try to search forums.