Would a chocolate teapot work in space?
October 7, 2010 5:14 AM Subscribe
Is there an atmospheric pressure at which the melting point of chocolate is higher than the boiling point of water?
Or– Would a chocolate teapot work in space?
Yes this question is inspired by the latest episode of The Naked Scientists podcast.
Or– Would a chocolate teapot work in space?
Yes this question is inspired by the latest episode of The Naked Scientists podcast.
The answer is likely yes- at even reasonably decent vacuum, water evaporates (boils) pretty quickly. I don't, however, know the vapor pressure of chocolate in its solid form. I would guess it's reasonably low, but I don't think anyone is likely to do that experiment in their vacuum system.
posted by JMOZ at 5:22 AM on October 7, 2010
posted by JMOZ at 5:22 AM on October 7, 2010
True- your water likely wouldn't be hot at all. Did you mean iced tea? In that case, you could do this right here on Earth.
posted by JMOZ at 5:23 AM on October 7, 2010
posted by JMOZ at 5:23 AM on October 7, 2010
Yes. According to the wikipedia chocolate article, good chocolate melts at around 34 C.
According to the water phase chart on this page, water boils at 34 C when the pressure is around 1500 Pascals, or 0.01 atm.
This is far above the pressure in space, even in low earth orbit. Unfortunately, in space, water would boil at a much lower temperature than chocolate would melt.
posted by Salvor Hardin at 5:29 AM on October 7, 2010
According to the water phase chart on this page, water boils at 34 C when the pressure is around 1500 Pascals, or 0.01 atm.
This is far above the pressure in space, even in low earth orbit. Unfortunately, in space, water would boil at a much lower temperature than chocolate would melt.
posted by Salvor Hardin at 5:29 AM on October 7, 2010
(that assumes that the melting point of chocolate is relatively independent of the atmospheric pressure, which I think is probably true)
posted by Salvor Hardin at 5:30 AM on October 7, 2010
posted by Salvor Hardin at 5:30 AM on October 7, 2010
(or maybe not - I couldn't find a good T-P phase chart for chocolate)
posted by Salvor Hardin at 5:31 AM on October 7, 2010 [1 favorite]
posted by Salvor Hardin at 5:31 AM on October 7, 2010 [1 favorite]
The problem is, you would have to drink it in a near-vaccuum, and it would be barely luke-warm. Oh, and your body would be boiling too.
posted by blue_beetle at 5:54 AM on October 7, 2010 [3 favorites]
posted by blue_beetle at 5:54 AM on October 7, 2010 [3 favorites]
...not to mention that your adorable chocolate teapot would implode with vacuum. Unless you poured your already-boiling-but-disappointingly-lukewarm-water into it after the boiling process was finished. Lets call this busted!
posted by genekelly'srollerskates at 6:11 AM on October 7, 2010 [3 favorites]
posted by genekelly'srollerskates at 6:11 AM on October 7, 2010 [3 favorites]
Best answer: not to mention that your adorable chocolate teapot would implode with vacuum
What? No, with equal pressures inside and out, there's no reason to expect that even something as fragile as solid chocolate would implode. A teapot doesn't hold pressure. It's under no stress.
MP is typically quite a bit less dependent on pressure than BP, so I don't have a hard time with Salvor Hardin's assumptions. I can't find a (low) P-T phase diagram for cholocate or cocoa butter, so that's probably as good as you'll get. Cocoa butter has some pretty unusual phase behaviour though. It's polymorphic, which means that it can form a whole range of different crystal types. If there's a low pressure form, your chocolate might be pretty unusual.
The chocolate is also going to outgass quickly under vacuum, losing the flavour compounds quickly. Only the low-vapour pressure compounds like the fats are going to remain. I recommend you eat your teapot quickly or it will go stale, like a months-old headless bunny.
posted by bonehead at 9:12 AM on October 7, 2010 [1 favorite]
What? No, with equal pressures inside and out, there's no reason to expect that even something as fragile as solid chocolate would implode. A teapot doesn't hold pressure. It's under no stress.
MP is typically quite a bit less dependent on pressure than BP, so I don't have a hard time with Salvor Hardin's assumptions. I can't find a (low) P-T phase diagram for cholocate or cocoa butter, so that's probably as good as you'll get. Cocoa butter has some pretty unusual phase behaviour though. It's polymorphic, which means that it can form a whole range of different crystal types. If there's a low pressure form, your chocolate might be pretty unusual.
The chocolate is also going to outgass quickly under vacuum, losing the flavour compounds quickly. Only the low-vapour pressure compounds like the fats are going to remain. I recommend you eat your teapot quickly or it will go stale, like a months-old headless bunny.
posted by bonehead at 9:12 AM on October 7, 2010 [1 favorite]
Complicated physics and ideal gas law aside: Yes, because you can brew tea in your fridge. The good parts of tea seeps out into liquid water at almost any temperature.
Your real question is could you boil water in solid chocolate and the answer is yes, probably, with sufficient vacuum.
posted by chairface at 9:27 PM on October 7, 2010
Your real question is could you boil water in solid chocolate and the answer is yes, probably, with sufficient vacuum.
posted by chairface at 9:27 PM on October 7, 2010
This thread is closed to new comments.
Yes.
Would a chocolate teapot work in space?
Normal brewing of tea doesn't require rapid evaporation (boiling); it requires heat and moisture. So no, not the way you're thinking.
posted by jon1270 at 5:22 AM on October 7, 2010 [1 favorite]