Talk:Dry ice

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Contents 1 Merge with carbon dioxide proposal 2 genericized trademark? 3 dry ice used to carbonate liquids? 4 Evironmental Impact 5 Safety Issues? 6 Other "dry ices"?

[edit] Merge with carbon dioxide proposal

I agree we should move the physical properties out to the CO2 article. Dry ice, however, is unique amongst solids in that most people think about it separately from the gas. Thus I think it should stay as a separate article. Samw 23:52, 18 October 2005 (UTC)

That is fine with me. It was the mismatched physical properties that I did not like. Feel free to do whatever you think will improve the article. Bobblewik 18:06, 19 October 2005 (UTC)

It should be mentioned that Dry Ice is also a very good store...

[edit] genericized trademark?

If dry ice is a genericized trademark, who once owned the name? -- stillnotelf 21:50, 22 July 2007 (UTC) IF DRY ICE IS PUT IN A CONTAINER AND NOT ALLOWED TO GAS OFF, WILL IT REMAIN A SOLID? MY EMAIL IS INFO@SOUTHERNCUSTOMCRAFTSMEN.COM I AM WORK ON AN IDEA AND COULD USE THE INPUT THANKS JMFG —Preceding unsigned comment added by 65.11.53.251 (talk) 23:27, 7 April 2008 (UTC)

[edit] dry ice used to carbonate liquids?

since when? The lack of citation for that comment doesn't help convince me that it's correct.Unexpectedbill3 17:17, 10 September 2007 (UTC)

I tend to agree; I can't find any easy references? Anyone else? If not, I think the use of dry ice to carbonate liquids should be removed from the article. Samw 00:49, 11 September 2007 (UTC)

There are a number of recipes out there that talk about using dry ice to carbonate liquids in the home (just Google something like "dry ice" recipe carbonated beverage); I have no idea if it's done industrially or not, though. DBowie 02:35, 16 September 2007 (UTC)

since co² dissolves in water I don't see why this wouldn't work. if you had some kind of container (pvc pipes maybe?) that can hold the pressure i'm sure you could get the same level of carbonation that the soda companies get. Don't think it would make sense in an industrial setting since converting the co² into solid is an extra step. Law & Disorder 23:31, 24 October 2007 (UTC)

update: i just tried the carbonation thing and it worked. a bit. it was like drinking almost flat soda. Law & Disorder 01:34, 25 October 2007 (UTC)

I tried it once and it tasted awful, kind of oily. I don't think the dry ice involved was "food-grade". --Itub 11:46, 25 October 2007 (UTC)

must have been caused by dirty manufacturing equipment. the co₂ should have no taste on it's own. Law & Disorder 21:30, 25 October 2007 (UTC)

For ten+ years I have used a 5+/- gallon stainless steel pressure vented soda fountain bottle to make carbonated water. Fill it with cold water, toss in 1-2 lbs of dry ice, close lid and walk away for an hour. Cost is 10-20 cents per gallon.Septagram (talk) 05:26, 19 December 2007 (UTC)

[edit] Evironmental Impact

"As the source of dry ice is typically pre-existing CO₂, there is no net impact on the greenhouse gas balance and the net environmental impact is zero." This statement is not completely true. Energy is required to convert CO₂ to the solid state through pressurising and refrigeration. Some 'new' CO₂ will be released into the atmosphere if the energy used originated from fossil fuels. No environmental free lunch here. —Preceding unsigned comment added by Johan H. Zietsman (talk • contribs) 14:15, 26 October 2007 (UTC)

Also, that "pre-existing" CO2 had to come from somewhere! I seriously doubt it was fixed from the air. CO2 is often produced from fossil fuels or minerals and as such it can certainly affect the greenhouse gas balance directly. Only when produced from fermentation or similar sources could one argue that the CO2 from the dry ice is "neutral". --Itub 15:20, 26 October 2007 (UTC)

don't see why not. Law & Disorder 02:40, 27 October 2007 (UTC)

[edit] Safety Issues?

You might want to include some info about safety ... I received a package recently with dry ice and it included all sorts of warnings about not touching it directly. —Preceding unsigned comment added by 68.14.111.240 (talk) 18:16, 6 December 2007 (UTC)

[edit] Other "dry ices"?

Is there a form of frozen or otherwise solid carbon monoxide? I can't find anything on carbon monoxide dry ice, or whatever it would be called. Explodingdog (talk) 16:48, 4 May 2008 (UTC)

no, carbon monoxide would not make a dry ice of any kind - melts at -205 °C (becoming a "wet" ice) and then boils at -192 °C normally, unlike carbon dioxide, which sublimes (changes from solid directly to gas) at −78 °C. To find another "dry ice", you would have to look for substances that are gases at room temperature, and sublime at atmospheric pressure. I am not sure there are any besides CO2. --Cubbi (talk) 17:20, 4 May 2008 (UTC)

To have something resembling "dry ice" you need to have a substance with a triple point pressure that is higher than the atmospheric pressure and a sublimation point below room temperature (this second requirement is so that the substance feels cold). From the common substances listed in this table [1], only acetylene meets the requirements, assuming you want your dry ice to be dry at sea level, which is 101 kPa. If you are willing to move up to the mountains, a couple other substances could work. For example, xenon and nitrous oxide could form dry ices in Mexico City, where the ambient pressure is around 78 kPa. And if you use a vacuum pump with low enough pressure, many other substances can be made to behave like dry ice. A couple of the substances in the table, graphite and uranium hexafluoride, have high enough triple point pressures so that they will never be a stable liquid under normal pressure, but their sublimation point is higher (for graphite much higher) than room temperature, so I am reluctant to call them "ices". --Itub (talk) 12:52, 6 May 2008 (UTC)

See also Wikipedia:Reference_desk/Science#Other_.22dry_ices.22.3F Samw (talk) 03:08, 7 May 2008 (UTC)

Moved from the Reference Desk:

Most substances have some range of pressure and temperature at which sublimation happens. Read the article for other examples of normal temperature and pressure sublimation. SpinningSpark 03:21, 5 May 2008 (UTC)

Thanks! So would you call naphthalene a "dry ice"? Or does the concept of "dry ice" even make sense scientifically and it's strictly a marketing term (which it was originally)? Samw (talk)

I wouldn't call it "a dry ice". Actually I've never thought of "dry ice" as a generic description for anything, rather just a name for a specific thing (solid CO₂). Naphthalene is not "ice" in the colloquial sense (it's not cold), so I would just call it a "solid". Maybe a "volatile solid". DMacks (talk) 05:19, 5 May 2008 (UTC)

Usually "ice" refers to water ice, and the special exception of dry ice is the name for solid CO₂. Not all cold solid crystals are ice; otherwise, steel and copper and quartz could be "ice". Nimur (talk) 16:43, 5 May 2008 (UTC)

In astronomy, they call any solid an ice that is lighter than rock. Ammonia ice and methane ice for instance as well as water and carbon dioxide.SpinningSpark 16:50, 5 May 2008 (UTC)

Getting slightly off topic, but I think astronomy is a bad guidance for such definitions. For astronomers, stars consist of hydrogen, helium and "metal"---where "metal" is everything heavier than helium... --Dapeteばか 19:11, 5 May 2008 (UTC)

To have something resembling "dry ice" you need to have a substance with a triple point pressure that is higher than the atmospheric pressure and a sublimation point below room temperature (this second requirement is so that the substance feels cold). From the common substances listed in this table [2], only acetylene (and CO2) meets the requirements, assuming you want your dry ice to be dry at sea level, which is 101 kPa. If you are willing to move up to the mountains, a couple other substances could work. For example, xenon and nitrous oxide could form dry ices in Mexico City, where the ambient pressure is around 78 kPa. And if you use a vacuum pump with low enough pressure, many other substances can be made to behave like dry ice. A couple of the substances in the table, graphite and uranium hexafluoride, have high enough triple point pressures so that they will never be a stable liquid under normal pressure, but their sublimation point is higher (for graphite much higher) than room temperature, so I am reluctant to call them "ices". --Itub (talk) 12:52, 6 May 2008 (UTC)