Demonstrating the diffusion of ammonia and hydrogen chloride

By Declan Fleming2021-06-21T10:08:00

A ruler against a glass tube with smoke forming inside

Source: © Declan Fleming

Revisiting and refining a classic diffusion demo with Declan Fleming

Diffusion is one of the most common concepts taught to students. One of its most ubiquitous demonstrations is the reaction of ammonia with hydrogen chloride – but that doesn’t mean it’s not worth revisiting. This way, we can ensure the best and safest results are achieved, as well as the most authentic discussion of their meaning.

In this Exhibition Chemistry, Declan Fleming revisits this classic diffusion demo – providing some great tips for doing it even better and considering the limitations of the conclusions that can be drawn from it.

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