RE: [math-fun] 177 million tons of ice???
Remember that the density of water is maximal at 4C, which, by coincidence (?) is the melting point of D2O. Depending on various temperatures, a D2O ice cube could pick up a coating of H2O or HDO ice, which might refloat it. Rich -----Original Message----- From: math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com [mailto:math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com]On Behalf Of Michael Kleber Sent: Wednesday, September 21, 2005 12:04 PM To: math-fun Subject: Re: [math-fun] 177 million tons of ice??? Tom Knight meant to write:
The molecular size and charge distribution is almost identical, so the crystals form without distinguishing between H2O and DHO. It would be rare to find any significant number of molecules of D2O.
[I corrected a DH2O to DHO, per later conversation.] Let's be clear here: heavy water is indeed D2O. You can't have a sample of pure, um, welterweight water, DHO: the hydrogen atoms are exchanged between water molecules all the time, so you'd really have a sample with half DHO and a quarter each H2O and D2O. Per Steve Gray's density calculation, you would need about (1/.914 - 1)/(20/18 - 1) = "85% heavy" water to make ice the density of normal liquid water. -- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen. _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
I can report experimentally that indeed D2O ice sinks. In addition, I made ice from a 17% H2O + 83% D2O solution, which was almost neutrally buoyant (I was off a bit, and it sank, but clearly was very close to buoyant). On Sep 21, 2005, at 2:11 PM, Schroeppel, Richard wrote:
Remember that the density of water is maximal at 4C, which, by coincidence (?) is the melting point of D2O. Depending on various temperatures, a D2O ice cube could pick up a coating of H2O or HDO ice, which might refloat it.
Rich
-----Original Message----- From: math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com [mailto:math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com]On Behalf Of Michael Kleber Sent: Wednesday, September 21, 2005 12:04 PM To: math-fun Subject: Re: [math-fun] 177 million tons of ice???
Tom Knight meant to write:
The molecular size and charge distribution is almost identical, so the crystals form without distinguishing between H2O and DHO. It would be rare to find any significant number of molecules of D2O.
[I corrected a DH2O to DHO, per later conversation.]
Let's be clear here: heavy water is indeed D2O. You can't have a sample of pure, um, welterweight water, DHO: the hydrogen atoms are exchanged between water molecules all the time, so you'd really have a sample with half DHO and a quarter each H2O and D2O.
Per Steve Gray's density calculation, you would need about (1/.914 - 1)/(20/18 - 1) = "85% heavy" water to make ice the density of normal liquid water.
-- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen.
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
Tom, Why did you buy the D20, surely not just to make ice cubes? Who sells the stuff, and at what price? Gene --- Tom Knight <tk@csail.mit.edu> wrote:
I can report experimentally that indeed D2O ice sinks. In addition, I made ice from a 17% H2O + 83% D2O solution, which was almost neutrally buoyant (I was off a bit, and it sank, but clearly was very close to buoyant).
On Sep 21, 2005, at 2:11 PM, Schroeppel, Richard wrote:
Remember that the density of water is maximal at 4C, which, by coincidence (?) is the melting point of D2O. Depending on various temperatures, a D2O ice cube could pick up a coating of H2O or HDO ice, which might refloat it.
Rich
-----Original Message----- From: math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com [mailto:math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com]On Behalf Of Michael Kleber Sent: Wednesday, September 21, 2005 12:04 PM To: math-fun Subject: Re: [math-fun] 177 million tons of ice???
Tom Knight meant to write:
The molecular size and charge distribution is almost identical, so the crystals form without distinguishing between H2O and DHO. It would be rare to find any significant number of molecules of D2O.
[I corrected a DH2O to DHO, per later conversation.]
Let's be clear here: heavy water is indeed D2O. You can't have a sample of pure, um, welterweight water, DHO: the hydrogen atoms are exchanged between water molecules all the time, so you'd really have a sample with half DHO and a quarter each H2O and D2O.
Per Steve Gray's density calculation, you would need about (1/.914 - 1)/(20/18 - 1) = "85% heavy" water to make ice the density of normal liquid water.
-- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen.
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
__________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com
Well, uh, yeah, I guess I did. Sigma-Aldrich 435767, 25g for $21.06. It's only 99% atomic purity, so it's much cheaper than the really pure stuff (which also takes out the tritium, btw). You wouldn't want to make lemonade from it, but pretty cheap, all things considered. I think they give the shipping address a once-over -- the order said "pending compliance review" when I first placed it. I suspect ordering from Tehran wouldn't work. On Sep 22, 2005, at 4:50 PM, Eugene Salamin wrote:
Tom,
Why did you buy the D20, surely not just to make ice cubes? Who sells the stuff, and at what price?
Gene
--- Tom Knight <tk@csail.mit.edu> wrote:
I can report experimentally that indeed D2O ice sinks. In addition, I made ice from a 17% H2O + 83% D2O solution, which was almost neutrally buoyant (I was off a bit, and it sank, but clearly was very close to buoyant).
On Sep 21, 2005, at 2:11 PM, Schroeppel, Richard wrote:
Remember that the density of water is maximal at 4C, which, by coincidence (?) is the melting point of D2O. Depending on various temperatures, a D2O ice cube could pick up a coating of H2O or HDO ice, which might refloat it.
Rich
-----Original Message----- From: math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com [mailto:math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com]On Behalf Of Michael Kleber Sent: Wednesday, September 21, 2005 12:04 PM To: math-fun Subject: Re: [math-fun] 177 million tons of ice???
Tom Knight meant to write:
The molecular size and charge distribution is almost identical, so the crystals form without distinguishing between H2O and DHO. It would be rare to find any significant number of molecules of D2O.
[I corrected a DH2O to DHO, per later conversation.]
Let's be clear here: heavy water is indeed D2O. You can't have a sample of pure, um, welterweight water, DHO: the hydrogen atoms are exchanged between water molecules all the time, so you'd really have a sample with half DHO and a quarter each H2O and D2O.
Per Steve Gray's density calculation, you would need about (1/.914 - 1)/(20/18 - 1) = "85% heavy" water to make ice the density of normal liquid water.
-- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen.
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
__________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
This stuff is cheaper than perfume! I can't imagine how 25g would be terribly useful, even for those in Tehran. Even if they made 100 or 1000 orders of this quantity. I thought that reactors used swimming pools full of the stuff. Perhaps this is the starting point for T2O ? What makes D2O toxic? At 02:05 PM 9/22/2005, Tom Knight wrote:
Well, uh, yeah, I guess I did. Sigma-Aldrich 435767, 25g for $21.06. It's only 99% atomic purity, so it's much cheaper than the really pure stuff (which also takes out the tritium, btw).
You wouldn't want to make lemonade from it, but pretty cheap, all things considered.
I think they give the shipping address a once-over -- the order said "pending compliance review" when I first placed it. I suspect ordering from Tehran wouldn't work.
participants (4)
-
Eugene Salamin -
Henry Baker -
Schroeppel, Richard -
Tom Knight