For an experiment, I'm adding several substances (as powders) to hydrogen chloride, and measuring the temperature changes to calculate enthalpy. What is a container I could perform it in (other than a styrofoam cup) that would minimise the heat lost to the surroundings?

I looked up using a vacuum flask of some sort, but would that be appropriate for this sort of reaction? The temperature is being measured via a temperature probe.

  • $\begingroup$ In endothermic reaction, if you start it at room temp., you'd have heat gain from the surroundings. $\endgroup$ – Mithoron Mar 25 '15 at 11:03
  • $\begingroup$ Yeah, some are endothermic and some are exo. I'm trying to minimise the effect of heat losses/gains on the change temperature. $\endgroup$ – deusy Mar 26 '15 at 6:47
  1. What is the scale?
  2. What is the budget?

Reactors are available from 250 mL up.

It might be cheaper to place a flask in a cut-off bottom of a suitable PE bottle and insulate it with PU foam from a DIY market.


A small Dewar cylinder might be an option too. The model 00C has a volume of 100 mL and lids are available too. Usually, these Dewars are used to store liquid nitrogen and cooling mixtures (2-propanol + dry ice, etc.) so I don't know how resistant the lid is towards $\ce{HCl}$ over time. In addition, this setup isn't as tight as a flask with hollow stoppers and/or a silicone seal if that's an issue.

  • $\begingroup$ The scale is pretty small, only $50cm^3$ of HCl. Would a vacuum flask, the sort shown here, reduce heat loss? $\endgroup$ – deusy Mar 25 '15 at 8:15
  • $\begingroup$ @deusy The Dewars might work too. I've updated my answer. $\endgroup$ – Klaus-Dieter Warzecha Mar 25 '15 at 10:00
  • $\begingroup$ Thanks! One last thing that you might have a suggestion for: What is the best way to stir the reaction once I add the powder? I'm measuring temperature with a temperature probe, but stirring with that is probably not a good idea because it may affect the temperature recordings. $\endgroup$ – deusy Mar 26 '15 at 7:19
  • $\begingroup$ Does the powder dissolve immediately? Are measurements on an inhomogenenous sample useful? Can you measure the temperature before, then add the powders to a stirred solution, stop stirring and start the real measurements? Maybe this is good enough for a separate question on experimental-chemistry. $\endgroup$ – Klaus-Dieter Warzecha Mar 26 '15 at 7:28
  • $\begingroup$ The new question is here. $\endgroup$ – deusy Mar 26 '15 at 8:46

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