I Made an Invisible Toxic Gas... For Science! | NOx #1

Описание: Nitric oxide has gone from Priestley’s mysterious “nitrous air” to one of the most important small molecules in modern chemistry and biology. In this video, we trace back to where it all started while preparing toxic, invisible nitric oxide in the lab and then turning it into a vivid brown cloud of nitrogen dioxide.

The video begins with the history: Joseph Priestley’s experiments on “different kinds of air” and how he first explored the composition of air. From there, we move into the fume hood and recreate a classic prep: reacting dilute nitric acid with copper metal to generate nitric oxide gas, highlighting the chemistry, the side products, and why this reaction became a staple of early pneumatic chemistry.

That freshly generated nitric oxide is then combined with oxygen in a gas jar, where it rapidly oxidises to nitrogen dioxide. The colourless gas becomes a dense brown fume, making the invisible visible and providing a clear window into changes in oxidation state and the chemistry of NOₓ species. Along the way, we discuss toxicity, why “you can’t see it” does not mean “it’s safe”.

If you enjoy experiments that mix history of chemistry, classic redox reactions, and visually striking gas demonstrations, this video is for you. It’s part of an ongoing series on reactive small molecules, building from historical experiments into modern chemical understanding.

If you liked the video, please leave a like, share it, and drop any questions or ideas for future gas‑chemistry episodes in the comments. And subscribe so you don’t miss upcoming videos on nitrogen oxides and other atmospheric and inorganic curiosities.

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References and further reading:

Molecular animations created with MolDraw – https://www.moldraw.com/

Priestley, J. Experiments and Observations on Different Kinds of Air. Cambridge University Press edition. https://doi.org/10.1017/CBO9781139644389