precipitate
American Heritage Dictionary:
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pre·cip·i·tate
(prĭ-sĭp'ĭ-tāt') 
v., -tat·ed, -tat·ing, -tates. v.tr.
precipitateness pre·cip'i·tate·ness n.
precipitative pre·cip'i·ta'tive adj.
precipitator pre·cip'i·ta'tor n.
v., -tat·ed, -tat·ing, -tates. v.tr.
- To throw from or as if from a great height; hurl downward: "The finest bridge in all Peru broke and precipitated five travelers into the gulf below" (Thornton Wilder).
- To cause to happen, especially suddenly or prematurely. See synonyms at speed.
- Meteorology. To cause (water vapor) to condense and fall from the air as rain, snow, sleet, or hail.
- Chemistry. To cause (a solid substance) to be separated from a solution.
- Meteorology. To condense and fall from the air as rain, snow, sleet, or hail.
- Chemistry. To be separated from a solution as a solid.
- To fall or be thrown headlong: an ailing economy that precipitated into ruin despite foreign intervention.
- Moving rapidly and heedlessly; speeding headlong.
- Acting with or marked by excessive haste and lack of due deliberation. See synonyms at impetuous, reckless.
- Occurring suddenly or unexpectedly.
- Chemistry. A solid or solid phase separated from a solution.
- A product resulting from a process, event, or course of action.
[Latin praecipitāre, praecipitāt-, to throw headlong, from praeceps, praecipit-, headlong : prae-, pre- + caput, capit-, head.]
precipitately pre·cip'i·tate·ly (-tĭt-lē) adv.precipitateness pre·cip'i·tate·ness n.
precipitative pre·cip'i·ta'tive adj.
precipitator pre·cip'i·ta'tor n.
USAGE NOTE The adjective precipitate and the adverb precipitately were once applied to physical steepness but are now used primarily of rash, headlong actions: Their precipitate entry into the foreign markets led to disaster. He withdrew precipitately from the race. Precipitous currently means "steep" in both literal and figurative senses: the precipitous rapids of the upper river; a precipitous drop in commodity prices. But precipitous and precipitously are also frequently used to mean "abrupt, hasty," which takes them into territory that would ordinarily belong to precipitate and precipitately: their precipitous decision to leave. This usage is a natural extension of the use of precipitous to describe a rise or fall in a quantity over time: a precipitous increase in reports of measles is also an abrupt or sudden event. Though this extended use of precipitous is well attested in the work of reputable writers, it is still widely regarded as an error.
Oxford Dictionary of Chemistry:
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precipitate
A suspension of small solid particles produced in a liquid by chemical reaction.
Roget's Thesaurus:
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precipitate
verb
- To put down, especially in layers, by a natural process: deposit. See increase/decrease.
adjective
- Characterized by unthinking boldness and haste: brash, foolhardy, harum-scarum, hasty, headlong, hotheaded, ill-considered, impetuous, improvident, impulsive, incautious, madcap, precipitant, rash1, reckless, slapdash, temerarious, unconsidered. See careful/careless.
- Happening quickly and without warning: abrupt, hurried, precipitant, sudden. See fast/slow/velocity, surprise/expect.
noun
- Matter that settles on a bottom or collects on a surface by a natural process: deposit, dreg (often used in plural), lees, precipitation, sediment. See leftover.
- Something brought about by a cause: aftermath, consequence, corollary, effect, end product, event, fruit, harvest, issue, outcome, ramification, result, resultant, sequel, sequence, sequent, upshot. See cause/effect.
Devil's Dictionary:
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precipitate
A cynical view of the world by Ambrose Bierce
adj.
Anteprandial.
Precipitate in all, this sinner
Took action first, and then his dinner.
Judibras
Word Tutor:
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precipitate
IN BRIEF: To cause to happen. Also: To separate from a solution.
It's queer how it is always one's virtues that precipitate one into disaster.
— Rebecca West (1892-1983)
LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!
Dictionary of Cultural Literacy: Science:
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precipitate
(pri-sip-uh-tayt, pri-sip-uh-tuht)
In chemistry, a solid material that is formed in a solution by chemical reactions and settles to the bottom of the container in which the reaction takes place. A precipitate may also be a substance removed from another by an artificial filter.
Oxford Dictionary of Biochemistry:
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precipitate
- to (cause to) come out of solution or suspension.
- substance or material that is precipitated.
| precipitant, precession, precess | |
| precipitating antibody, precipitin, precipitin reaction |
Saunders Veterinary Dictionary:
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precipitate
1. to cause settling of a soluble substance in solution.
2. a deposit of solid particles settled out of a solution.
3. occurring with undue rapidity, as precipitate labor.
Mosby's Dental Dictionary:
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precipitate
(prē-sip′i-tāt)
n
n
An insoluble solid substance that forms from chemical reactions between solutions.
Random House Word Menu:
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categories related to 'precipitate'
- Materials, Formations, and Substances - precipitate: rock formed from discharge or evaporation of water
- Substances, Particles, and Atomic Architecture - precipitate: solid produced by reaction occurring in a solution
Bradford's Crossword Solver's Dictionary:
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precipitate
See crossword solutions for the clue Precipitate.
Wikipedia on Answers.com:
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Precipitation (chemistry)
This article is about the chemical phenomemon. For other uses, see Precipitation.
"Precipitate" redirects here. For the album by Interpol, see Precipitate EP.
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This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2008) |
Precipitation is the formation of a solid in a solution or inside another solid during a chemical reaction or by diffusion in a solid. When the reaction occurs in a liquid, the solid formed is called the Precipitate, or when compacted by a centrifuge, a pellet. The liquid remaining above the solid is in either case called the supernate or supernatant. Powders derived from precipitation have also historically been known as flowers.
Natural methods of precipitate include settling or sedimentation, where a solid forms over a period of time due to ambient forces like gravity or centrifugation. During chemical reactions, precipitation may also occur particularly if an insoluble substance is introduced into a solution and the density happens to be greater (otherwise the precipitate would float or form a suspension). With soluble substances, precipitation is accelerated once the solution becomes supersaturated.
In solids, precipitation occurs if the concentration of one solid is above the solubility limit in the host solid, due to e.g. rapid quenching or ion implantation, and the temperature is high enough that diffusion can lead to segregation into precipitates. Precipitation in solids is routinely used to synthesize nanoclusters.[1]
An important stage of the precipitation process is the onset of nucleation. The creation of a hypothetical solid particle includes the formation of an interface, which requires some energy based on the relative surface energy of the solid and the solution. If this energy is not available, and no suitable nucleation surface is available, supersaturation occurs.
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Contents
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Applications
Precipitation reactions can be used for making pigments, removing salts from water in water treatment, and in classical qualitative inorganic analysis.
Precipitation is also useful to isolate the products of a reaction during workup. Ideally, the product of the reaction is insoluble in the reaction solvent. Thus, it precipitates as it is formed, preferably forming pure crystals. An example of this would be the synthesis of porphyrins in refluxing propionic acid. By cooling the reaction mixture to room temperature, crystals of the porphyrin precipitate, and are collected by filtration:[2]
Precipitation may also occur when an antisolvent (a solvent in which the product is insoluble) is added, drastically reducing the solubility of the desired product. Thereafter, the precipitate may easily be separated by filtration, decanting, or centrifugation). An example would be the synthesis of chromic tetraphenylporphyrin chloride: water is added to the DMF reaction solution, and the product precipitates.[3] Precipitation is also useful in purifying products: crude bmim-Cl is taken up in acetonitrile, and dropped into ethyl acetate, where it precipitates.[4]
In metallurgy, precipitation from a solid solution is also a useful way to strengthen alloys; this process is known as solid solution strengthening.
Representation using chemical equations
See also: solubility product
An example of a precipitation reaction: Aqueous silver nitrate (AgNO3) is added to a solution containing potassium chloride (KCl), the precipitation of a white solid, silver chloride is observed. (Zumdahl, 2005)
- AgNO3 (aq) + KCl (aq) → AgCl (s) + KNO3 (aq)
The silver chloride (AgCl) has formed a solid, which is observed as a precipitate.
This reaction can be written emphasizing the dissociated ions in a combined solution. This is known as the ionic equation.
- Ag+ (aq) + NO3− (aq) + K+ (aq) + Cl− (aq) → AgCl (s) + K+ (aq) + NO3− (aq)
A final way to represent a precipitate reaction is known as a net ionic reaction. In this case, any spectator ions (those that do not contribute to the reaction) are left out of the formula completely. This simplifies the above equations to the following:
- Ag+ (aq) + Cl− (aq) → AgCl (s)
Cation sensitivity
See also: Qualitative inorganic analysis
Precipitate formation is useful in the detection of the type of cation in salt. To do this, an alkali first reacts with the unknown salt to produce a precipitate that is the hydroxide of the unknown salt. To identify the cation, the color of the precipitate and its solubility in excess are noted. Similar processes are often used to separate chemically similarly.
Digestion
Digestion, or precipitate ageing, happens when a freshly formed precipitate is left, usually at a higher temperature, in the solution from which it precipitates. It results in cleaner and bigger particles. The physico-chemical process underlying digestion is called Ostwald ripening.
References
- ^ Dhara, S. (2007). "Formation, Dynamics, and Characterization of Nanostructures by Ion Beam Irradiation". Critical Reviews in Solid State and Materials Sciences 32 (1): 1–50. doi:10.1080/10408430601187624.
- ^ A. D. Adler; F. R. Longo; J. D. Finarelli; J. Goldmacher; J. Assour; L. Korsakoff (1967). "A simplified synthesis for meso-tetraphenylporphine". J. Org. Chem. 32 (2): 476–476. doi:10.1021/jo01288a053.
- ^ Alan D. Adler; Frederick R. Longo; Frank Kampas; Jean Kim (1970). "On the preparation of metalloporphyrins". Journal of Inorganic and Nuclear Chemistry 32 (7): 2443. doi:10.1016/0022-1902(70)80535-8.
- ^ Dupont, J., Consorti, C., Suarez, P., de Souza, R. (2004), "Preparation of 1-Butyl-3-methyl imidazolium-based Room Temperature Ionic Liquids", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=v79p0236; Coll. Vol. 10: 184
Further reading
- Zumdahl, Steven S. (2005). Chemical Principles (5th ed.). New York: Houghton Mifflin. ISBN 0-618-37206-7.
- Smith, Mark (1993). Principles of Science.
External links
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Wikimedia Commons has media related to: Solid precipitation |
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Translations:
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Precipitate
Dansk (Danish)
v. tr. - fremskynde, bundfælde, udskille
v. intr. - styrte
adj. - brat, hovedkulds
n. - bundfald
Nederlands (Dutch)
neerslaan (chemisch), neerslaan, condenseren, abrupt veroorzaken, slingeren, languit vallen, overhaasten, overhaastig, dat wat uit een oplossing neerslaat
Français (French)
v. tr. - (Chim, Météo, gén) précipiter
v. intr. - (Chim) précipiter, (Météo) être précipité
adj. - précipité, prompt
n. - (Chim) précipité
Deutsch (German)
v. - sich niederschlagen, stürzen, beschleunigen, ausfällen, kondensieren
adj. - überstürzt, eilig
n. - Niederschlag, Kondensat
Ελληνική (Greek)
v. - κατακρημνίζω, γκρεμίζω, επισπεύδω, (χημ.) υγροποιώ
adj. - βιαστικός, εσπευσμένος
n. - ίζημα, (χημ.) κατακρήμνισμα
Italiano (Italian)
precipitare, depositarsi, precipitato
Português (Portuguese)
v. - precipitar
adj. - precipitado
n. - precipitado (m)
Русский (Russian)
ввергнуть, выпадать (об осадках), ускорить, стремительный, опрометчивый, осадок
Español (Spanish)
v. tr. - precipitarse, condensarse
v. intr. - precipitarse, condensarse
adj. - precipitado
n. - precipitado
Svenska (Swedish)
v. - störta, påskynda, plötsligt framkalla, fälla ut (kem.), kondensera (fys.)
adj. - brådstörtad, plötslig, förhastad, besinningslös
n. - utfällning, kondensat
中文（简体）(Chinese (Simplified))
猛抛, 促成, 使陷入, 猛地落下, 突如其来的, 贸然轻率的, 陡然下降的, 沉淀物
中文（繁體）(Chinese (Traditional))
v. tr. - 猛拋, 促成, 使陷入
v. intr. - 猛地落下
adj. - 突如其來的, 貿然輕率的, 陡然下降的
n. - 沈澱物
한국어 (Korean)
v. tr. - 거꾸로 떨어뜨리다
v. intr. - 갑자기 빠지다
adj. - 거꾸로의, 줄달음치는
n. - 침전(물)
日本語 (Japanese)
n. - 沈殿物
v. - 真っ逆さまに落とす, 陥らせる, 沈殿する, 沈殿させる, 突然引き起こす, 凝結させる, 促進する
adj. - 大急ぎの, 軽率な
العربيه (Arabic)
(فعل) يلقي, يقذف, يندفع, يتهور (صفه) مترسب (الاسم) نتيجه, نتاج, ثمرة
עברית (Hebrew)
v. tr. - זירז, החיש, הטיל, השליך, עיבה (גז לנוזל)
v. intr. - יצר משקע מחומר הנמצא באוויר, הפריד חומר הנמצא בתמיסה
adj. - נמהר, לא-שקול
n. - חומר מופרד, משקע
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American Heritage Dictionary
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
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Oxford Dictionary of Chemistry
A Dictionary of Chemistry. Sixth Edition. Copyright © Market House Books Ltd, 2008. All rights reserved.
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Dictionary of Cultural Literacy: Science
The New Dictionary of Cultural Literacy, Third Edition Edited by E.D. Hirsch, Jr., Joseph F. Kett, and James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin. All rights reserved.
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This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article Precipitation (chemistry).
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