Editing Base (chemistry) (section)

==Strong bases==
A strong base is a basic chemical compound that can remove a proton (H<sup>+</sup>) from (or ''[[deprotonate]]'') a molecule of even a very weak acid (such as water) in an acid–base reaction. Common examples of strong bases include hydroxides of [[Alkali metal|alkali metals]] and [[Alkaline earth metal|alkaline earth metals]], like [[sodium hydroxide]] and [[calcium hydroxide]], respectively. Due to their low [[solubility]], some bases, such as alkaline earth hydroxides, can be used when the solubility factor is not taken into account.{{sfnp|Zumdahl|DeCoste|2013|page=255}}

One advantage of this low solubility is that "many [[Antacid|antacids]] were [[Suspension (chemistry)|suspensions]] of metal hydroxides such as [[aluminium hydroxide]] and [[magnesium hydroxide]]";{{sfnp|Zumdahl|DeCoste|2013|page=256}} compounds with low solubility and the ability to stop an increase in the concentration of the hydroxide ion, preventing the harm of the tissues in the mouth, oesophagus, and stomach.{{sfnp|Zumdahl|DeCoste|2013|page=256}} As the reaction continues and the salts dissolve, the [[stomach acid]] reacts with the hydroxide produced by the suspensions.{{sfnp|Zumdahl|DeCoste|2013|page=256}}

Strong bases hydrolyze in water almost completely, resulting in the [[leveling effect]].<ref name=Gilbert /> In this process, the water molecule combines with a strong base, due to the water's amphoteric ability; and, a hydroxide ion is released.<ref name=Gilbert /> 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:

{|
|[[Lithium hydroxide]]||LiOH
|-
|[[Sodium hydroxide]]||NaOH
|-
|[[Potassium hydroxide]]||KOH
|-
|[[Rubidium hydroxide]]||RbOH
|-
|style="border-bottom-style:dashed;"|[[Cesium hydroxide]]||style="border-bottom-style:dashed;"|CsOH
|-
|[[Magnesium hydroxide]]||{{chem|Mg(OH)|2}}
|-
|[[Calcium hydroxide]]||{{chem|Ca(OH)|2}}
|-
|[[Strontium hydroxide]]||{{chem|Sr(OH)|2}}
|-
|style="border-bottom-style:dashed;"|[[Barium hydroxide]]||style="border-bottom-style:dashed;"|{{chem|Ba(OH)|2}}
|-
|[[Tetramethylammonium hydroxide]]||{{chem|N(CH|3|)|4|OH}}
|-
|[[Guanidine]]||{{chem|HNC(NH|2|)|2}}
|}

The cations of these strong bases appear in the first and second groups of the periodic table (alkali and earth alkali metals). Tetraalkylated ammonium hydroxides are also strong bases since they dissociate completely in water. [[Guanidine]] is a special case of a species that is exceptionally stable when protonated, analogously to the reason that makes [[perchloric acid]] and [[sulfuric acid]] very strong acids.

Acids with a p''K<sub>a</sub>'' of more than about 13 are considered very weak, and their [[conjugate base]]s are strong bases.

===Superbases===
{{Main|Superbase}}
Group 1 salts of [[carbanion]]s, [[azanide ion|amide ions]], 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 ''[[superbase]]s'', and it is impossible to keep them in aqueous solutions because they are stronger bases than the [[hydroxide]] ion (See the [[leveling effect]].) For example, the ethoxide ion (conjugate base of ethanol) undergoes this reaction quantitatively in presence of water.<ref name="AlkoxideLibreText">{{cite web |title=10.4.1. Alkoxide Ions |url=https://chem.libretexts.org/Courses/Purdue/Purdue_Chem_26100%3A_Organic_Chemistry_I_(Wenthold)/Chapter_10%3A_Alcohols/10.4_Acidity_of_Alcohols/10.4.1._Alkoxide_Ions |website=Chemistry Libretexts |date=16 July 2015 |publisher=LibreText |access-date=28 October 2022}}</ref>

:<chem>CH3CH2O- + H2O -> CH3CH2OH + OH-</chem>

Examples of common superbases are:
*[[n-Butyllithium|Butyl lithium]] (n-C<sub>4</sub>H<sub>9</sub>Li)
*[[Lithium diisopropylamide]] (LDA) [(CH<sub>3</sub>)<sub>2</sub>CH]<sub>2</sub>NLi 
*[[Lithium diethylamide]] (LDEA) {{chem|(C|2|H|5|)|2|NLi}}
*[[Sodium amide]] (NaNH<sub>2</sub>)
*[[Sodium hydride]] (NaH)
*[[Lithium bis(trimethylsilyl)amide]] {{chem|[(CH|3|)|3|Si]|2|NLi}}

Strongest superbases are synthesised in only gas phase:
*[[Ortho-diethynylbenzene dianion]] (C<sub>6</sub>H<sub>4</sub>(C<sub>2</sub>)<sub>2</sub>)<sup>2−</sup> (the strongest superbase ever synthesized)  
*[[Meta-diethynylbenzene dianion]] (C<sub>6</sub>H<sub>4</sub>(C<sub>2</sub>)<sub>2</sub>)<sup>2−</sup> (second strongest superbase)
*[[Para-diethynylbenzene dianion]] (C<sub>6</sub>H<sub>4</sub>(C<sub>2</sub>)<sub>2</sub>)<sup>2−</sup> (third strongest superbase)
*[[Lithium monoxide anion]] (LiO<sup>−</sup>) was considered the strongest superbase before diethynylbenzene dianions were created.