Supersaturated Sodium Acetate - Tales from the Prep Room

A beautiful transformation and a curious conundrum. Watch as Andy turns liquid into solid in a matter of seconds, experimenting with a supersaturated solution of sodium acetate.
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It just takes one small nudge to spark the transformation of a seemingly stable liquid into a solid. The liquid – a supersaturated solution of sodium acetate – consists of water with more dissolved sodium acetate salt than can be stably sustained. When Andy drops in a salt crystal, he provides the kick needed to start the transformation into the more thermodynamically favourable solid state.

At least, that’s what’s meant to happen. Just like science in a lab, science in the Prep Room doesn’t always go to plan first time. It’s a process of trial and error, explaining the unexpected, and exploring the phenomena at work. Curiously, when he goes to start the process, Andy finds that the crystallisation has half-completed – something which should, in theory, be impossible, because once one crystal forms it should kick-start the full process throughout the liquid.



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