Sublimation (phase transition): Difference between revisions

Revision as of 05:39, 17 January 2024

Revision as of 10:38, 21 January 2024

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{{distinguish|subliminal stimuli}}

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<!-- READ BEFORE EDIT, sublimation refers to ALL THREE CASES:

1. theSublime transitiongradually: below triple point and left of solid-gas boundary

(similar to evaporation)

(bottom left of solid in phase diagram)

2. theSublime transitionrapidly: below triple point and at solid-gas boundary

(similar to boiling)

3. theSublime transitiongradually: above triple point and belowleft of solid-liquid boundary (yes, solid sublimes above triple point)

(also similar to evaporation, just higher pressure)

(top left of solid in phase diagram)

These three cases jointly exhaust the solid space in the phrase diagram. This make sense, after all, technically, all solids sublime (depending mostly on vapour pressure, which is very situational).

One may notice there is a fourth case in the solid space, that is, at the solid-liquid boundary. It is uncertain if the solid canis still sublimeconsidered whilesubliming WHILE melting, thoseand whoin knowcase mayit clarify.is, it --><!--would checkingbe somesubliming onlinegradually, Englishthose dictionaries:who know PLEASE CLARIFY.

-->

One may notice there is a fourth case in the solid space, that is, at the solid-liquid boundary. It is uncertain if the solid can still sublime while melting, those who know may clarify. --><!-- checking some online English dictionaries:

<!--

checking some online English dictionaries:

1. sublime and sublimate are both valid, and both have some other meanings

https://www.merriam-webster.com/dictionary/sublime#did-you-know

(also almost every dictionary)

2. sublimate may mean the product

https://www.merriam-webster.com/dictionary/sublimate#dictionary-entry-2

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https://chambers.co.uk/search/?query=sublimate&title=21st

https://www.wordreference.com/definition/sublimate

3. sublimation may also mean itself followed by deposition

https://www.collinsdictionary.com/dictionary/english/sublime

https://www.dictionary.com/browse/sublime

4. sublimation seems used to mean deposition alone but this meaning is now completely obsolete, few if any online dictionary has such meaning as of 2023, the archaic use is likely phased out -->

-->

4. sublimation seems used to mean deposition alone but this meaning is now completely obsolete, few if any online dictionary has such meaning as of 2023, the archaic use is likely phased out -->

[[File:Nickelocen an einem Kühlfinger.jpg|thumb|right|Dark green [[crystals]] of [[nickelocene]], sublimed and freshly deposited on a [[cold finger]]]]

[[File:Sublimation of iodine.webm|thumb|Sublimation of iodine]]

'''Sublimation''' is the [[Phase transition|transition of a substance]] directly from the [[solid]] to the [[gas]] state, without passing through the [[liquid]] state.<ref>{{cite book |last1=Whitten |first1=Kenneth W. |last2=Gailey |first2=Kenneth D. |last3=Davis |first3=Raymond E. |title=General chemistry |url=https://archive.org/details/generalchemistry00whit_0 |url-access=registration |date=1992 |publisher=Saunders College Publishing |isbn=0-03-072373-6 |page=[https://archive.org/details/generalchemistry00whit_0/page/475 475] |edition=4th}}</ref> The verb form of sublimation is ''sublime'', or less preferably, ''sublimate''.<ref name=":0">{{cite Merriam-Webster|Sublimate}}</ref> ''Sublimate'' also refers to the product obtained by sublimation.<ref name=":0" /><ref>[https://www.collinsdictionary.com/dictionary/english/sublimate "Sublimate"]. [[Collins English Dictionary#CollinsDictionary.com|CollinsDictionary.com Dictionary]].</ref> The point at which sublimation occurs rapidly (for further details, see [[Sublimation (phase transition)#False correspondence with vaporization|below]]) is called critical sublimation point, or simply [[sublimation point]]. Notable examples include sublimation of [[dry ice]] at room temperature and atmospheric pressure, and that of solid [[iodine]] with heating.

The reverse process of sublimation is [[deposition (phase transition)|''deposition'']] (also called ''desublimation''), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state.<ref name="DepositionDef">{{cite journal |title=Controlling condensation and frost growth with chemical micropatterns |first1=Jonathan B. |last1=Boreyko |first2=Ryan R. |last2=Hansen |first3=Kevin R. |last3=Murphy |first4=Saurabh |last4=Nath |first5=Scott T. |last5=Retterer |first6=C. Patrick |last6=Collier |journal=Scientific Reports |year=2016 |volume=6 |pages=19131 |doi=10.1038/srep19131 |pmid=26796663 |pmc=4726256 |bibcode=2016NatSR...619131B}}</ref>

All solids sublime, though most sublime at extremely low rates that are hardly detectable. At [[standard conditions for temperature and pressure|normal pressures]], most [[chemical compound]]s and [[chemical element|elements]] possess three different states at different [[temperature]]s. In these cases, the transition from the [[solid]] to the [[gas]] state requires an intermediate liquid state. The pressure referred to is the ''[[partial pressure]]'' of the substance, not the ''total'' (e.g. atmospheric) pressure of the entire system. Thus, any solid can sublime if its [[vapour pressure]] is higher than the surrounding partial pressure of the same substance, and in some cases, sublimes at an appreciable rate (e.g. water ice just below 0&nbsp;°C).

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=== False correspondence with vaporization ===

While [[vaporization]] (from liquid to gas) is divided into two types; vaporization on the surface of the liquid is called [[evaporation]]; and vaporization at the boiling point with formation of bubbles in the interior of the liquid is called [[boiling]], there is ''no'' such distinction for the solid-to-gas transition. Solid-to-gas transition is always called sublimation in both corresponding cases.

==== Potential distinction ====

For clarification, a distinction between the two corresponding cases is needed. With reference to a [[phase diagram]], the sublimation that occurs left of the solid-gas boundary, the triple point or the solid-liquid boundary (corresponding to evaporation in vaporization) may be called ''gradual sublimation''; and the substance ''sublime gradually'', regardless of rate. The sublimation that occurs at the solid-gas boundary (critical sublimation point) (corresponding to boiling in vaporization) may be called ''rapid sublimation'', and the substance ''sublime rapidly''. Note that both the words "gradual" and "rapid" have acquired special meanings in such context and no longer describes the rate of sublimation.<!-- This distinction is used only on this page and nowhere else, to minimize confusion. If there is a better distinction, change it along with the examples. If this violates the policy of Wikipedia, please delete this paragraph and nothing else, and if possible, also provide a better solution. -->

=== Misuse for chemical reaction ===

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=== Historical definition ===

Sublimation is historically used as a generic term to describe a two-step phase transition ― a solid-to-gas transition (sublimation in a more precise definition) followed by a gas-to-solid transition ([[deposition (phase transition)|deposition]]).<ref>{{Dictionary.com|Sublime}}</ref><ref>[https://www.collinsdictionary.com/dictionary/english/sublime "Sublime"]. [[Collins English Dictionary#CollinsDictionary.com|CollinsDictionary.com Dictionary]].</ref> (See [[Sublimation (phase transition)#Historical usage|below]])

==Examples==

[[File:Comparison carbon dioxide water phase diagrams.svg|thumb|upright=2|Comparison of phase diagrams of carbon dioxide (red) and water (blue) showing the carbon dioxide sublimation point (middle-left) at 1 atmosphere. As dry ice is heated, it crosses this point along the bold horizontal line from the solid phase directly into the gaseous phase. Water, on the other hand, passes through a liquid phase at 1 atmosphere.]]

===Carbon dioxide===

[[File:Dry Ice Vapor (17490553041).jpg|thumb|[[Dry ice]] subliming in air]]

Solid [[carbon dioxide]] ([[dry ice]]) sublimes everywhererapidly along the linesolid-gas boundary (sublimation point) below the triple point (e.g., at the temperature of −78.5&nbsp;°C (194.65 K, {{convert|194.65|K|F|disp=output only}}) at [[atmospheric pressure]]), whereas its melting into liquid CO₂ can occur along the solid-liquid lineboundary ([[melting point]]) at pressures and temperatures above the triple point (i.e., 5.1 atm, −56.6&nbsp;°C).

===Water===

[[Snow]] and [[ice]] sublime, although more slowly,gradually at temperatures below the freezing/[[solid-liquid boundary (melting point]]) temperature line at(generally 0&nbsp;°C), forand at partial pressures below the triple point pressure of {{convert|612|Pa|atm|abbr=on}}, at a low rate.<ref>{{cite journal |last=Fassnacht |first=S. R. |year=2004 |title=Estimating Alter-shielded gauge snowfall undercatch, snowpack sublimation, and blowing snow transport at six sites in the coterminous USA |journal=Hydrol. Process |doi=10.1002/hyp.5806 |bibcode=2004HyPr...18.3481F |volume=18 |issue=18 |pages=3481–3492|s2cid=129927018 }}</ref> In [[freeze-drying]], the material to be dehydrated is frozen and its water is allowed to sublime under reduced pressure or vacuum. The loss of snow from a [[snowfield]] during a cold spell is often caused by sunshine acting directly on the upper layers of the snow. [[Ablation]]Sublimation of ice is a processfactor thatto includes sublimation andthe erosive wear of [[glacier ice]], also called [[ablation]] in [[glaciology]].{{citation needed|date=October 2021}}

===Naphthalene===

[[Naphthalene]], an organic compound commonly found in pesticides such as [[mothball]]s, sublimes easily because it is made of non-polar molecules that are held together only by [[Van der Waals force|van der Waals]] intermolecular forces. Naphthalene is a solid that sublimes readilygradually at [[standard conditions for temperature and pressure|standard atmospheric temperature]]<ref>

{{cite book

|last=Caroll |first=J.

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|isbn=9780128005750

|page=16

}}</ref>, at a high rate, with the boiling pointcritical (sublimation point) at around 80{{nbsp}}°C or 176{{nbsp}}°F.<ref>

{{cite web

|author=Staff writer(s)

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[[File:Camphor sublimation 1.jpg|thumb|upright|[[Camphor]] subliming in a [[cold finger]]. The crude product in the bottom is dark brown; the white purified product on the bottom of the cold finger above is hard to see against the light background.]]

[[Iodine]] gradually sublimes and produces visible fumes on gentle heating at [[standard conditions for temperature and pressure|standard atmospheric temperature]]. It is possible to obtain liquid iodine at atmospheric pressure by controlling the temperature at just between the melting point and the boiling point of iodine. In [[forensic science]], iodine vapor can reveal latent [[fingerprint]]s on paper.<ref>{{cite book

|last=Girard |first=James

|year= 2011