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Comment by sp332 | Hacker News Reader

Hydrogen sulfide, for example, reacts with four molecules of FOOF to give sulfur hexafluoride, 2 molecules of HF and four oxygens...and 433 kcal

433 kilocalaries from 5 molecules? Am I reading that right?

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It gives 433 kcal/mol, i. e. 433 kilocalories from 5 * 6.02E23 molecules. It is approximately 68g FOOF and 132g HS. (about 2oz and 5oz respectively)

Is that a lot? The same amount of fat can be burned for more energy?

It's not just that it's a lot of energy, but also that it's being released all at once, and into just 200g of matter. It's not all heat energy, either; an uncomfortably large portion of the energy is released as an explosion!

Yes, but what's important is the rate. Power is the measure of calories per hour (or joules per second). Fat (and food in general) is extremely energy dense, but that energy can only be released relatively slowly.

This is the same reason why TNT is used for demolition while gasoline is used for engines. Gasoline delivers 15 times the energy of an equal weight of TNT, but TNT's energy release is much more rapid (it can also do so without air, the other big reason for blowing things up with TNT).

Yeah, that made me do a double-take too. Can you imagine what a gram of the stuff would do?

That's why he was laughing at the fact that a company is apparently willing to sell and ship it in kilos.

He's probably talking about mols of the stuff.

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