# Where is the chemical energy from?
**URL:** https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263
**Category:** Factual Questions
**Created:** [July 20, 2001, 11:39pm UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263 "2001-07-20T23:39:26Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@Mirage](https://boards.straightdope.com/u/Mirage)
#### Post date: [July 20, 2001, 11:39pm UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/1 "2001-07-20T23:39:26Z")
I remember this big deal in high school chemestry about the discrepencies in mass between two molecules of hydrogen and one of helium, and how this missing mass was converted to energy according to the e=mc2 that we all have grown to love.
My question is: does this mass-to-energy thing happen in chemical reactions? We’re dealing with the electro-magnetic force now instead of the strong (??) nuclear force, but I can’t shake the feeling that somebody told me this once. I’m hoping that someone at the SDMB can straighten this whole issue out for me…
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### Author:  [@armedmonkey](https://boards.straightdope.com/u/armedmonkey)
#### Post date: [July 20, 2001, 11:54pm UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/2 "2001-07-20T23:54:17Z")
Short answer:No.
That would be “cold fusion”. Which has never been proven.
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### Author:  [@rjk](https://boards.straightdope.com/u/rjk)
#### Post date: [July 21, 2001, 2:40am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/3 "2001-07-21T02:40:07Z")
Short answer: Yes. (Sorry, Beeblebrox.)
As **Beeblebrox** points out, cold fusion doesn’t work, but the energy of chemical reactions does come from mass changes. Those changes are just very much smaller than the ones from nuclear reactions, and are mostly fairly easy to reverse.
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### Author:  [@RyanD004](https://boards.straightdope.com/u/RyanD004)
#### Post date: [July 21, 2001, 2:58am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/4 "2001-07-21T02:58:39Z")
Maybe I’m wrong,but I always thought that in a chemical reaction no mass was lost,just sort of moved around. Essentially… it takes energy to put some molecules together, so if you take them apart that energy is given back. I always believed in conservation of mass for non-nuclear reactions.
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### Author:  [@Ring](https://boards.straightdope.com/u/Ring)
#### Post date: [July 21, 2001, 4:23am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/5 "2001-07-21T04:23:02Z")
There is no such thing as "conversion, the mass change is the consequence of energy release, not the cause. When you have an exothermic reaction, some of the energy which was stored in the system is released as kinetic energy. After being transferred to the surrounding material, the original system is left with less energy, hence less mass. And it is just as true about chemical reactions as about nuclear ones.
The only difference is quantitative, not qualitative. The typical relative mass change in a chemical reaction is of the order of 10[sup]-9[/sup] - 10[sup]-10[/sup] , to small to be directly observable. The typical relative mass change in nuclear reactions is of the order of 10[sup]-3[/sup], which is quite easily observable. Why the difference? Not because there is different physics in action, just because the fields involved in nuclear binding are much stronger, thus the changes in binding energies are also proportionally stronger.
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [July 21, 2001, 5:11am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/6 "2001-07-21T05:11:45Z")
Yeah, what Ring said.
It’s misleading to think of **conversion** between energy and mass. Einstein told us that that the two are **equivalent**. If you have a sealed box and you poured some energy into it, it will get heavier by the amount predicted by e=mc^2. Without opening the box you can’t tell if the energy is stored as energy (say, by charging a battery, or compressing a spring) or by converting it into matter. In fact, such a distinction is impossible.
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### Author:  [@armedmonkey](https://boards.straightdope.com/u/armedmonkey)
#### Post date: [July 21, 2001, 5:51am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/7 "2001-07-21T05:51:04Z")
> [@](#):
>
> \*Originally posted by scr4 \*
> \*\*Without opening the box you can’t tell if the energy is stored as energy (say, by charging a battery, or compressing a spring) or by converting it into matter. In fact, such a distinction is impossible. \*\*
Jeez, if you are going to bring Shroedingers’s cat into this, at least do a better job of explaining it.
Mirage, the short answer is still no.
Forget the quantum mechanics and just think in terms of Newton and Einstein.
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### Author:  [@Dr.Lao](https://boards.straightdope.com/u/Dr.Lao)
#### Post date: [July 21, 2001, 6:23am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/8 "2001-07-21T06:23:35Z")
**Beeblebrox** , what **scr4** said about energy and matter has nothing to do with Schrödinger’s cat or quantum mechanics, and I doubt he/she meant it to. The short answer is still yes and all you need is Einstein in order to say it. Cecil says:
> [@](#):
>
> Permit me to quote from Space and Time in Special Relativity by N. David Mermin, a book I read myself to sleep with every night: “A loss of mass occurs whenever internal energy (nuclear, electrical, chemical, etc.) is converted into energy of motion. Only in the nuclear case is the amount of energy so large that [it results] in an observable change in mass, but in principle E=mc^2 is as descriptive of a chemical explosive, a gasoline engine, or a flying bird [or, I might add, a flying human] as it is of a nuclear explosion.” Case closed.
I concur.
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### Author:  [@armedmonkey](https://boards.straightdope.com/u/armedmonkey)
#### Post date: [July 21, 2001, 6:58am UTC](https://boards.straightdope.com/t/where-is-the-chemical-energy-from/73263/9 "2001-07-21T06:58:55Z")
Damn, all that tuition spent on physical chemistry classes and I still apparently don’t know jack.
Please allow me the dignity to slink away quietly.
(shuffle, shuffle, shuffle)