strong base

• 強塩基

WordNet

1. any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water; "bases include oxides and hydroxides of metals and ammonia" (同)alkali
2. (numeration system) the positive integer that is equivalent to one in the next higher counting place; "10 is the radix of the decimal system" (同)radix
3. the bottom side of a geometric figure from which the altitude can be constructed; "the base of the triangle"
4. situate as a center of operations; "we will base this project in the new lab"
5. a place that the runner must touch before scoring; "he scrambled to get back to the bag" (同)bag
6. installation from which a military force initiates operations; "the attack wiped out our forward bases" (同)base of operations
7. a support or foundation; "the base of the lamp" (同)pedestal, stand
8. (electronics) the part of a transistor that separates the emitter from the collector
9. a flat bottom on which something is intended to sit; "a tub should sit on its own base"
10. the principal ingredient of a mixture; "glycerinated gelatin is used as a base for many ointments"; "he told the painter that he wanted a yellow base with just a hint of green"; "everything she cooked seemed to have rice as the base"
11. the place where you are stationed and from which missions start and end (同)home
12. (anatomy) the part of an organ nearest its point of attachment; "the base of the skull"
13. the bottom or lowest part; "the base of the mountain"
14. illegitimate (同)baseborn
15. of low birth or station (`base is archaic in this sense); "baseborn wretches with dirty faces"; "of humble (or lowly) birth" (同)baseborn, humble, lowly
16. not adhering to ethical or moral principles; "base and unpatriotic motives"; "a base, degrading way of life"; "cheating is dishonorable"; "they considered colonialism immoral"; "unethical practices in handling public funds" (同)immoral
17. having or showing an ignoble lack of honor or morality; "that liberal obedience without which your army would be a base rabble"- Edmund Burke; "taking a mean advantage"; "chokd with ambition of the meaner sort"- Shakespeare; "something essentially vulgar and meanspirited in politics" (同)mean, meanspirited
18. (used of metals) consisting of or alloyed with inferior metal; "base coins of aluminum"; "a base metal"
19. debased; not genuine; "an attempt to eliminate the base coinage"
20. of verbs not having standard (or regular) inflection; "`sing is a strong verb"
21. freshly made or left; "a warm trail"; "the scent is warm" (同)warm
22. having strength or power greater than average or expected; "a strong radio signal"; "strong medicine"; "a strong man"
23. not faint or feeble; "a strong odor of burning rubber"
24. having a base; "firmly based ice"
25. having a base of operations (often used as a combining form); "a locally based business"; "an Atlanta-based company"; "carrier-based planes"

PrepTutorEJDIC

1. 《文》(人や人の行動・孝えが)『卑しい』,下劣な / (金属が)質の劣った;(貨幣が)粗悪な
2. 『基礎』,根拠 / 『基部』,基底,土台 / 『根拠地』,基地 / (野球の)塁,ベース / 主成分;塩基(酸と反応シテ塩(官)を生じる化合物) / (数学で図形の)底;底辺;基線 / (…に)…‘の'『基礎をおく』《+『名』+『on』(『upon』)+『名』》
3. (身体的に)『力の強い』 / (身体が)『じょうぶな』,健康な / 勢力(権力)のある,有力な / (物が)『がんじょうな』,堅固な / (精神的・道徳的に)『強い』 / 説得力のある,効果的な / (味・においが)いやな,不快な / (動きが)激しい,速い / (程度が)強い,強烈な,濃い / アルコール分の多い / 《数詞の後に用いて》…の人員の / 強く,強力に;激しく,盛んに
4. basisの複数形

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/07/10 07:49:25」(JST)

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For the term in genetics, see base (genetics)

Acids and bases
Acid dissociation constant Acid-base extraction Acid–base reaction Acid–base titration Dissociation constant Acidity function Buffer solutions pH Proton affinity Amphoterism Self-ionization of water Acid strength
Acid types
Brønsted Lewis Mineral Organic Strong Superacids Weak
Base types
Brønsted Lewis Organic Strong Superbases Non-nucleophilic Weak

In chemistry, a base is a substance that, in aqueous solution, is slippery to the touch, tastes bitter, changes the colour of indicators (e.g., turns red litmus paper blue), reacts with acids to form salts, and promotes certain chemical reactions (base catalysis). Examples of bases are the hydroxides of the alkali and alkaline earth metals (NaOH, Ca(OH)₂, etc). Such substances produce hydroxide ions (OH^-) in aqueous solutions, and are thus classified as Arrhenius bases.

For a substance to be classified as an Arrhenius base, it must produce hydroxide ions in solution—in order to do so, Arrhenius believed the base must contain hydroxide in the formula. This makes the Arrhenius model limited, as it cannot explain the basic properties of aqueous solutions of ammonia (NH₃) or its organic derivatives (amines). In the more general Brønsted–Lowry acid–base theory, a base is a substance that can accept hydrogen ions (H⁺)—otherwise known as protons. In the Lewis model, a base is an electron pair donor.

In water, by altering the autoionization equilibrium, bases give solutions with a hydrogen ion activity lower than that of pure water, i.e., a pH higher than 7.0 at standard conditions. A soluble base is called an alkali if it contains and releases OH^- ions quantitatively. However, it is important to realize that basicity is not the same as alkalinity. Metal oxides, hydroxides, and especially alkoxides are basic, and counteranions of weak acids are weak bases.

Bases can be thought of as the chemical opposite of acids. Bases and acids are seen as opposites because the effect of an acid is to increase the hydronium (H₃O⁺) concentration in water, whereas bases reduce this concentration. A reaction between an acid and base is called neutralization. In a neutralization reaction, an aqueous solution of a base reacts with an aqueous solution of an acids to produce a solution of water and salt in which the salt separates into its component ions. If the aqueous solution is saturated with a given salt solute, any additional such salt precipitates out of the solution.

Properties

Some general properties of bases include

• Slimy or soapy feel on fingers, due to saponification of the lipids in human skin.
• Concentrated or strong bases are caustic on organic matter and react violently with acidic substances.
• Aqueous solutions or molten bases dissociate in ions and conduct electricity.
• Reactions with indicators: bases turn red litmus paper blue, phenolphthalein pink, keep bromothymol blue in its natural colour of blue, and turn methyl orange yellow.
• The pH level of a basic solution is higher than 7.
• Bases are bitter in taste.

Neutralization of acids

When dissolved in water, the strong base sodium hydroxide ionizes into hydroxide and sodium ions:

NaOH → Na+
+ OH−

and similarly, in water the acid hydrogen chloride forms hydronium and chloride ions:

HCl + H
2O → H
3O+
+ Cl−

When the two solutions are mixed, the H
3O+
and OH−
ions combine to form water molecules:

H
3O+
+ OH−
→ 2 H
2O

If equal quantities of NaOH and HCl are dissolved, the base and the acid neutralize exactly, leaving only NaCl, effectively table salt, in solution.

Weak bases, such as baking soda or egg white, should be used to neutralize any acid spills. Neutralizing acid spills with strong bases, such as sodium hydroxide or potassium hydroxide can cause a violent exothermic reaction, and the base itself can cause just as much damage as the original acid spill.

Alkalinity of non-hydroxides

Bases are generally compounds that can neutralize an amount of acids. Both sodium carbonate and ammonia are bases, although neither of these substances contains OH−
groups. Both compounds accept H⁺ when dissolved in protic solvents such as water:

Na₂CO₃ + H₂O → 2 Na⁺ + HCO₃^- + OH^-

NH₃ + H₂O → NH₄⁺ + OH^-

From this, a pH, or acidity, can be calculated for aqueous solutions of bases. Bases also directly act as electron-pair donors themselves:

CO₃^2- + H⁺ → HCO₃^-

NH₃ + H⁺ → NH₄⁺

Carbon can act as a base as well as nitrogen and oxygen. This occurs typically in compounds such as butyl lithium, alkoxides, and metal amides such as sodium amide. Bases of carbon, nitrogen and oxygen without resonance stabilization are usually very strong, or superbases, which cannot exist in a water solution due to the acidity of water. Resonance stabilization, however, enables weaker bases such as carboxylates; for example, sodium acetate is a weak base.

Strong bases

A strong base is a basic chemical compound that deprotonates very weak acids in an acid-base reaction. Common examples of strong bases include hydroxides of alkali metals and alkaline earth metals like NaOH and Ca(OH)
2. Very strong bases can even deprotonate very weakly acidic C–H groups in the absence of water. Here is a list of several strong bases:

• Potassium hydroxide (KOH)
• Barium hydroxide (Ba(OH)
  2)
• Cesium hydroxide (CsOH)
• Sodium hydroxide (NaOH)
• Strontium hydroxide (Sr(OH)
  2)
• Calcium hydroxide (Ca(OH)₂)
• Lithium hydroxide (LiOH)
• Rubidium hydroxide (RbOH)

The cations of these strong bases appear in the first and second groups of the periodic table (alkali and earth alkali metals).

Acids with a pK_a of more than about 13 are considered very weak, and their conjugate bases are strong bases.

Superbases

Main article: Superbase

Group 1 salts of carbanions, amides, and hydrides tend to be even stronger bases due to the extreme weakness of their conjugate acids, which are stable hydrocarbons, amines, and dihydrogen. Usually these bases are created by adding pure alkali metals such as sodium into the conjugate acid. They are called superbases, and it is impossible to keep them in water solution because they are stronger bases than the hydroxide ion. As such, they deprotonate the conjugate acid water. For example, the ethoxide ion (conjugate base of ethanol) in the presence of water undergoes this reaction.

CH
3CH
2O−
+ H
2O → CH
3CH
2OH + OH−

Here are some superbases:

• Butyl lithium (n-C₄H₉Li)
• Lithium diisopropylamide (LDA) [(CH₃)₂CH]₂NLi
• Lithium diethylamide (LDEA) (C
  2H
  5)
  2NLi
• Sodium amide (NaNH₂)
• Sodium hydride (NaH)
• Lithium bis(trimethylsilyl)amide [(CH
  3)
  3Si]
  2NLi

Bases as catalysts

Basic substances can be used as insoluble heterogeneous catalysts for chemical reactions. Some examples are metal oxides such as magnesium oxide, calcium oxide, and barium oxide as well as potassium fluoride on alumina and some zeolites. Many transition metals make good catalysts, many of which form basic substances. Basic catalysts have been used for hydrogenations, the migration of double bonds, in the Meerwein-Ponndorf-Verley reduction, the Michael reaction, and many other reactions.

See also

• Acids
• Acid-base reactions
• Base-richness (used in ecology, referring to environments)
• Conjugate base
• Titration

References

UpToDate Contents

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• 1. 強イオンおよび酸塩基障害の解析（スチュワート法） strong ions and the analysis of acid base disturbances stewart approach
• 2. 臍帯血酸塩基分析 umbilical cord blood acid base analysis
• 3. 胎児の酸塩基の生理学 fetal acid base physiology
• 4. Chapter 10A：酸と塩基 chapter 10a acids and bases
• 5. 単純性および混合性酸塩基障害 simple and mixed acid base disorders

English Journal

• pK(a) determinations of xanthene derivates in aqueous solutions by multivariate analysis applied to UV-Vis spectrophotometric data.

• Batistela VR, Pellosi DS, de Souza FD, da Costa WF, de Oliveira Santin SM, de Souza VR, Caetano W, de Oliveira HP, Scarminio IS, Hioka N.SourceDepartamento de Quimica, Universidade Estadual de Maringa, Av. Colombo, 5.790, CEP 87.020-900, Maringa, Parana, Brazil.
• Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.Spectrochim Acta A Mol Biomol Spectrosc.2011 Sep;79(5):889-97. Epub 2011 Apr 2.
• Xanthenes form to an important class of dyes which are widely used. Most of them present three acid-base groups: two phenolic sites and one carboxylic site. Therefore, the pK(a) determination and the attribution of each group to the corresponding pK(a) value is a very important feature. Attempts to
• PMID 21550841

• Organic extracts of urban air pollution particulate matter (PM2.5)-induced genotoxicity and oxidative stress in human lung bronchial epithelial cells (BEAS-2B cells).

• Oh SM, Kim HR, Park YJ, Lee SY, Chung KH.SourceHoseo Toxicological Research Center, Hoseo University, 165, Sechul-ri, Baebang-myun, Asan, Chungnam, 336-795, Republic of Korea.
• Mutation research.Mutat Res.2011 Aug 16;723(2):142-51. Epub 2011 Apr 16.
• Traffic is a major source of particulate matter (PM), and ultrafine particulates and traffic intensity probably contribute significantly to PM-related health effects. As a strong relationship between air pollution and motor vehicle-originated pollutants has been shown to exist, air pollution genotox
• PMID 21524716

Japanese Journal

• 日本における想定被害地震を対象とした高層免震建物の地震応答性状とアスペクト比効果に関する一考察--強震動水平・上下両成分同時入力が高層免震建物の地震応答性状に及ぼす効果に関する研究(その3)

• 池田 雄一,長橋 純男
• 日本建築学会構造系論文集 76(660), 281-290, 2011-02
• NAID 40018716228

• Physical Education, Exercise Science and Pedagogy: Forging the Links

• Culpan Ian,Draper Nick,Stevens Susannah
• International Journal of Sport and Health Science advpub(0), 1104120075, 2011
• … Reforms have seen the emergence of strong socio-cultural and socio-critical curriculum perspectives and corresponding developments in the utilisation of alternative pedagogies. … However there appears to be little if any base-line data relating to the exercise sciences in PETE contexts. …
• NAID 130000649438

Related Links

• Base (chemistry) - Wikipedia, the free encyclopedia

A strong base is a basic chemical compound that is able to deprotonate very weak acids in an acid-base reaction. Common examples of strong bases are the hydroxides of alkali metals and alkaline earth metals ...

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リンク元	「強塩基」
関連記事	「base」「strong」

「強塩基」

　　[★]

英

strong base

関

塩基

「base」

　　[★]

• n.

• 基礎、基盤、根拠、基本、基底

関

basal、base、basement、basic、basis、element、elementary、evidence、foundation、fundamental、fundamentals、fundus、ground、infrastructure、reason

　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　

「strong」

　　[★]

• adj.

• 強い

関

intense、robust