Base (chemistry)

basebasicbasesstrong basebasicityalkalinechemical baseproton acceptorweak basechemically basic
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH − ) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH − ions.wikipedia
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Hydroxide

OHhydroxide ionOH −
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH − ) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH − ions.
It functions as a base, a ligand, a nucleophile, and a catalyst.

Acid

acidicacidityacids
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH − ) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH − ions.
Acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals (like calcium) to form salts.

Acid catalysis

acid catalystacid-catalyzedacid-base catalysis
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH − ) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH − ions.
In acid catalysis and base catalysis, a chemical reaction is catalyzed by an acid or a base.

Sodium hydroxide

caustic sodaNaOHsodium
Examples of bases are the hydroxides of the alkali metals and the alkaline earth metals (NaOH, Ca(OH) 2, etc.—see alkali hydroxide and alkaline earth hydroxide). 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.
Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns.

Alkali metal

alkali metalsalkaligroup 1
Examples of bases are the hydroxides of the alkali metals and the alkaline earth metals (NaOH, Ca(OH) 2, etc.—see alkali hydroxide and alkaline earth hydroxide).
This new element was noted by him to form compounds similar to those of sodium and potassium, though its carbonate and hydroxide were less soluble in water and more alkaline than the other alkali metals.

PH

pH levelneutralpH value
In water, by altering the autoionization equilibrium, bases yield solutions in which the hydrogen ion activity is lower than it is in pure water, i.e., the water has a pH higher than 7.0 at standard conditions.
In chemistry, pH is a scale used to specify how acidic or basic a water-based solution is.

Calcium hydroxide

slaked limelimehydrated lime
Examples of bases are the hydroxides of the alkali metals and the alkaline earth metals (NaOH, Ca(OH) 2, etc.—see alkali hydroxide and alkaline earth hydroxide).
Aqueous solutions of calcium hydroxide are called limewater and are medium strength bases that reacts with acids and can attack some metals such as aluminium (amphoteric hydroxide dissolving at high pH) while protecting other metals from corrosion such as iron and steel by passivation of their surface.

Alkali

alkalinealkalisalkalinity
A soluble base is called an alkali if it contains and releases OH − ions quantitatively.
In chemistry, an alkali (from Arabic: al-qaly "ashes of the saltwort") is a basic, ionic salt of an alkali metal or alkaline earth metal chemical element.

Alkalinity

alkalinealkalictotal alkalinity
However, it is important to realize that basicity is not the same as alkalinity.
(It should not be confused with basicity which is an absolute measurement on the pH scale.) Alkalinity is the strength of a buffer solution composed of weak acids and their conjugate bases.

Alkoxide

alkoxidesethoxidemetal alkoxide
Metal oxides, hydroxides, and especially alkoxides are basic, and conjugate bases of weak acids are weak bases. This occurs typically in compounds such as butyl lithium, alkoxides, and metal amides such as sodium amide.
Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands.

Conjugate acid

conjugate baseconjugateconjugate bases
Metal oxides, hydroxides, and especially alkoxides are basic, and conjugate bases of weak acids are weak bases.
A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed by the reception of a proton (H + ) by a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a hydrogen ion.

Aqueous solution

aqueouswater solubilityaqueous solutions
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH − ) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH − ions.
Acids and bases are aqueous solutions, as part of their Arrhenius definitions.

Neutralization (chemistry)

neutralizationneutralizeneutralized
A reaction between an acid and a base is called neutralization.
In chemistry, neutralization or neutralisation (see spelling differences) is a chemical reaction in which an acid and a base react quantitatively with each other.

Amine

aminoaminesamino group
This makes the Arrhenius model limited, as it cannot explain the basic properties of aqueous solutions of ammonia (NH 3 ) or its organic derivatives (amines).
In organic chemistry, amines (, UK also ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair.

Oxide

oxidesmetal oxideO
Metal oxides, hydroxides, and especially alkoxides are basic, and conjugate bases of weak acids are weak bases.
Oxides typically react with acids or bases, sometimes both.

Lewis acids and bases

Lewis acidLewis baseLewis acids
In the Lewis model, a base is an electron pair donor.
A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct.

Litmus

litmus paperlitmus testLitmus test (chemistry)
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH − ) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH − ions.
The main use of litmus is to test whether a solution is acidic or basic.

Ammonia

NH 3 anhydrous ammonialiquid ammonia
This makes the Arrhenius model limited, as it cannot explain the basic properties of aqueous solutions of ammonia (NH 3 ) or its organic derivatives (amines).
The nitrogen atom in the molecule has a lone electron pair, which makes ammonia a base, a proton acceptor.

PH indicator

indicatorindicatorschemical indicator
A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually.

Potassium hydroxide

KOHcaustic potashpotassium
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.
Along with sodium hydroxide (NaOH), this colorless solid is a prototypical strong base.

N-Butyllithium

n''-butyllithiumbutyllithiumn''-BuLi
This occurs typically in compounds such as butyl lithium, alkoxides, and metal amides such as sodium amide.
Also, it is broadly employed as a strong base (superbase) in the synthesis of organic compounds as in the pharmaceutical industry.

Svante Arrhenius

Svante August ArrheniusArrheniusArrhenius, Svante August
Arrhenius believed that in order to do so, the base must contain hydroxide in the formula.
In an extension of his ionic theory Arrhenius proposed definitions for acids and bases, in 1884.

Water

H 2 OHOliquid water
In a neutralization reaction, an aqueous solution of a base reacts with an aqueous solution of an acid to produce a solution of water and salt in which the salt separates into its component ions.
Acids have pH values less than 7 while bases have values greater than 7.

Guanidine

guanidiniumguanidinoGuanidines
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.
It is a strong base that is used in the production of plastics and explosives.