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So I was trying out the sodium acetate trihydrate 'hot ice' experiment, and my 300ml test worked great. So, naturally, more is better right? (cringe)

Now I have a 1000ml in a pyrex beaker cooling down, and I am belatedly wondering if this is going to generate too much heat when I set it off. I'd imagine the beaker itself is safe, I don't imagine it would do anything to the granite countertop, but it is resting on a plastic cutting board, which could conceivably melt.

How much of this can I make before I'm doing something risky?

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    $\begingroup$ I bet it was fun to watch - to much fun to think in measuring the temperature change ;) Small volumes (<< 300 mL) are actually used as pocket warmers and usually considered to be safe. I'd say the 1000 mL experiment is safe too, but you might want to skip the cutting board and place the beaker in a larger glass bowl ("Kristallisierschale"). In the end, it's your granite table, not mine. $\endgroup$ – Klaus-Dieter Warzecha Dec 27 '14 at 11:08
  • $\begingroup$ According to About Chemistry: it states The heat generated by the crystallization of a refrigerated sodium acetate solution should not present a burn hazard. I hope nobody would pour it on their skin to test the validity of the statement. chemistry.about.com/od/homeexperiments/a/… $\endgroup$ – LDC3 Dec 27 '14 at 14:33
  • $\begingroup$ Ahh. I remember the "more is better" idea we had at uni when we were told to destroy some leftover sodium from an overfilled and un-reglementary storage that had been "discovered". It turns out there is a limit, and that limit is way before tossing 3 kgs of sodium into a lake from a dingy. It is not fun trying to row a dinghy that is on fire, with oars that are burning, on a lake that is locally very much like concentrated lye.. $\endgroup$ – Stian Yttervik Jan 28 at 13:37
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The heat generated increases directly with the amount of sodium acetate trihydrate used, but the maximum temperature, ignoring surface effects, should not change at all. After all, if the heat in 300 ml is used to raise the temperature of 300 ml of substance, or if 300 kg is used to raise the temperature of 300 kg, it's being spread out proportionately. No matter how much you use, it won't exceed ~58 C

However, do not try this in a container that would not allow room for expansion, e.g. a glass bottle, as in crystallizing, sodium acetate trihydrate might take up more room. See warning at http://chemmovies.unl.edu/chemistry/dochem/DoChem058.html. You could safely do this on a polyethylene cutting board, though, which melts at ~100 C

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