On Fri, Oct 24, 2014 at 10:57 PM, Jed Rothwell <jedrothw...@gmail.com>

> H Veeder <hveeder...@gmail.com> wrote:
>> Ok so you can design a calorimeter to detect this particular endothermic
>>> reaction, however, if you don't know a-priori what type of endothermic
>>> reaction or what energy source is involved a "standard" calorimeter might
>>> fail to detect it.
>>> Harry
>> ‚ÄčAnother potential problem is that a calorimeter designed to detect an
>> exothermic reaction might prevent an unknown endothermic reaction which is
>> a prerequisite for the exothermic reaction. ‚Äč
> A calorimeter cannot be designed for exothermic or endothermic reactions.
> If it can measure an increase in heat, it can measure a decrease with the
> same accuracy and precision. When a reaction produces heat and then stops
> producing it, the calorimeter always shows that decline. You always see the
> power fluctuating up and down; the calorimeter always measures in both
> directions equally well. With an endothermic reaction the decline goes
> below the starting point. That's the only difference. The calorimeter does
> not care about that.
> If the cell was storing up energy, you would see it for sure. Scott Little
> showed a beautiful example of this once. He put a rechargeable battery into
> a calorimeter and charged it up. There was a deficit comparing electricity
> to the rising temperature. Then he discharged the battery through a
> resister in the cell. All the lost energy came back. The balance was close
> to zero.
> - Jed

Was the temperature of the water in the calorimeter rising during charging?


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