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[Q] Does heavy water ice sink or float in regular water?


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#1 Moontanman

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Posted 27 January 2009 - 10:09 PM

Would ice composed of heavy water sink or float in regular water? I saw a show the other night were they were able to tell the difference between the two by freezing water and then seeing if the ice floated or not.

#2 belovelife

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Posted 27 January 2009 - 10:54 PM

A form of water in which the hydrogen atoms of mass 1 (1H) ordinarily present in water are replaced by deuterium (D or 2H), the heavy stable isotope of hydrogen of mass 2. The molecular formula of heavy water is D2O (or 2H2O). See also Deuterium.

Because the mass difference between 1H and 2H is the largest for any pair of stable (nonradioactive) isotopes in the periodic table, many of the physical and chemical properties of the pure isotopic species and their respective compounds differ to a significant extent. Selected physical properties of 1H2O and 2H2O are compared in the table.

Physical properties of ordinary and heavy water Property
1H2O
2H2O (D2O)

Molecular weight, 12C scale
18.015
20.028

Melting point, °C
0.00
3.81

Normal boiling point, °C
100.00
101.42

Temperature of maximum density, °C
3.98
11.23

Density at 25°C, g/cm3
0.99701
1.1044

Critical constants

Temperature, °C
374.1
371.1

Pressure, mPa
22.12
21.88

Volume, cm3/mol
55.3
55.0

Viscosity at 55°C, mPa · s
0.8903
1.107

Refractive index, nD20
1.3330
1.3283

#3 Moontanman

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Posted 27 January 2009 - 10:58 PM

Thanks for the stats belove but will heavy water ice float in regular water?

#4 belovelife

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Posted 27 January 2009 - 11:04 PM

water
0.998 g/cm³ (liquid at 20 °C, 1 atm)

Density at 25°C, g/cm3
0.99701
1.1044

heavy water solid
1.0177 g/cm3, solid (at m.p)

so it looks like it would sink :)

#5 Moontanman

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Posted 27 January 2009 - 11:08 PM

Cool , thanks

#6 freeztar

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Posted 28 January 2009 - 03:06 AM

[quote name='belovelife']A form of water in which the hydrogen atoms of mass 1 (1H) ordinarily present in water are replaced by deuterium (D or 2H), the heavy stable isotope of hydrogen of mass 2. The molecular formula of heavy water is D2O (or 2H2O). See also Deuterium.

Because the mass difference between 1H and 2H is the largest for any pair of stable (nonradioactive) isotopes in the periodic table, many of the physical and chemical properties of the pure isotopic species and their respective compounds differ to a significant extent. Selected physical properties of 1H2O and 2H2O are compared in the table.

Physical properties of ordinary and heavy water Property
1H2O
2H2O (D2O)

Molecular weight, 12C scale
18.015
20.028

Melting point, °C
0.00
3.81

Normal boiling point, °C
100.00
101.42

Temperature of maximum density, °C
3.98
11.23

Density at 25°C, g/cm3
0.99701
1.1044

Critical constants

Temperature, °C
374.1
371.1

Pressure, mPa
22.12
21.88

Volume, cm3/mol
55.3
55.0

Viscosity at 55°C, mPa · s
0.8903
1.107

Refractive index, nD20
1.3330
1.3283[/quote]

Please indicate your source(s). In this case:

heavy water: Definition from Answers.com

As this is a copyrighted source, please abide by fair use when quoting from such sources. It's good practice to use the [quote] tags as well.

#7 belovelife

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Posted 28 January 2009 - 03:10 AM

Ok,
You did get the source right.
that and wikipedia.

#8 Michaelangelica

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Posted 28 January 2009 - 04:11 AM

I vaguely remember reading that some iceberg ice is so old and compressed that it is as hard as steel and may sink in water.

#9 goku

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Posted 28 January 2009 - 12:13 PM

eleventh hour? if so i saw it to

#10 Michaelangelica

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Posted 28 January 2009 - 11:16 PM

I don't remember

Fresh water icebergs would have to float in a salty sea.
(Although 80-90% is below the waterline)

But ice that has been compressed for a few millennia has virtually no air in it and might sink in fresh water??

The best Google could come up with was a note that glacial ice with sediment in it may sink ("Black icebergs")
SEE
The Alaska Almanac: Facts about Alaska - Google Book Search

where is an Antarctic Geek when you need one?

#11 Moontanman

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Posted 28 January 2009 - 11:47 PM

I can see glacial ice with sediment in it sinking but if it's freshwater ice no matter if it has air in it or not it will float. If I remember correctly sea ice or ice that forms in sea water sheds it's salt content as it freezes so sea ice is freshwater ice and should always float.

Goku, I saw it on the eleventh hour too. I wasn't sure if it was true or not. The idea that one isotope could be heavy enough to affect if it floats or not seems almost counter intuitive me but I guess it's correct.

#12 belovelife

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Posted 29 January 2009 - 06:24 AM

Blue ice (glacial) - Wikipedia, the free encyclopedia)

Although I don't know if it sinks or floats.

#13 Moontanman

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Posted 29 January 2009 - 11:24 AM

http://en.wikipedia....ue_ice_(glacial)

Although I don't know if it sinks or floats.


Belove, why would you give a link to nothing? What is the point? Are you hoping no one would check?

#14 belovelife

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Posted 29 January 2009 - 11:32 AM

fixed

#15 HydrogenBond

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Posted 29 January 2009 - 08:53 PM

D2O ice can will sink in H2O, but with a qualifier.

Maximum density of H2O is at 3.984 C; 999.972 kg/m3 (liquid)

Density of D2O ice at its melting point is 1017.5 kg/m3 (3.82 C).

However, H2O can also exist with the atomic weight of the O "18" instead of "16". In that case, the H20 (18) has a density of 1112.49 kg/m3 at 4.211 C. So D2O ice would float on that type of water.

#16 Michaelangelica

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Posted 29 January 2009 - 09:55 PM

Belove, why would you give a link to nothing? What is the point? Are you hoping no one would check?

It worked straight away for me- to Wiki article.

Perhaps I should get my daughter in Tasmania to contact the Antarctic division of whatever down there. They have huge cold rooms filled with masses of drilled ice cores from Antarctica. We only need them to drop an old, deep bit into a glass of tap water. That shouldn't be too hard?:sherlock:

#17 freeztar

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Posted 30 January 2009 - 03:11 AM

It worked straight away for me- to Wiki article.

Perhaps I should get my daughter in Tasmania to contact the Antarctic division of whatever down there. They have huge cold rooms filled with masses of drilled ice cores from Antarctica. We only need them to drop an old, deep bit into a glass of tap water. That shouldn't be too hard?:confused:


No need. Boil some water and make some ice cubes. The boiling will remove almost all of the gases from the water. The ice will float just like any other. The only exceptions seem to be if additional elements are present in the ice or if the water is "heavy water".