In chemistry and biochemistry, acid dissociation constant, the acidity constant, or the acid-ionization constant (Ka) is a specific type of equilibrium constant that indicates the extent of dissociation of hydrogen ions from an acid. It is important to remember that the term [H2O] is omitted from the general equilibrium constant expression. While strong acids dissociate practically completely in solution and consequently have large acidity constants, weak acids do not fully dissociate and gen ...
There exists a relationship between the value of Ka for an acid HA and the value of Kb for its conjugate base A–. Since adding the ionization reaction for HA and the ionization reaction of A– always gives the reaction for the self-ionization of water, the product of the acidity and basicity constants gives the dissociation constant of water (Kw), which is 1 ...
By analogy, one can define the basicity constant (Kb) and the pKb of the conjugate base A–:
pKb = −log10Kb
This is the dissociation constant for the equi ...
Chloric acid, HClO3, is an oxoacid of chlorine, and the formal precursor of chlorate salts. It is a strong acid (pKa ≈ −1) and oxidising agent.
It is prepared by the reaction of sulfuric acid with barium chlorate, the insoluble barium sulfate being removed by precipitation:
Ba(ClO3)2 + H2SO4
An aldehyde is either a functional group consisting of a terminal carbonyl group or a compound containing a terminal carbonyl group.
(Where -R represents the carbon chain.)
Aldehyde - Structure.
The aldehyde functional group is a carbon atom bonded to a carbonyl group and a hydrogen atom.
Aldehyde - α carbon & α hydrogen.
An α (alpha) carbon is a carbon adjacent to a carbonyl group. An α hydrogen is a hydrogen atom bonded to the α carbon. The pKa of an α ...
Acridine, C13H9N, is an organic compound and a nitrogen heterocycle. The compound is similar to anthracene with the central benzene ring replaced by a pyridine ring. Acridine is colorless and was first isolated from crude coal tar. It is a raw material for the production of dyes. Many acridines also have antiseptic properties such as Proflavine. Acridine and their derivatives are DNA and RNA binding ...
Chemistry resources is a collection of links and references that are useful for chemistry-related work. This includes free online chemical databases, publications, patents, computer programs, and various tools.
Chemistry resources - Free online resources.
Chemistry resources - Databases.
Chemical catalog Compounds, analytical data
Chmoogle The free chemistry search engine
PubChem Compound, substance, and bioactivity data
NCI Databa ...
Cysteine is a naturally occurring hydrophobic amino acid which has a sulfhydryl group and is found in most proteins, though only in small quantities. When it is exposed to air it oxidizes to form cystine, which is two cysteine molecules joined by a disulfide bond. N-acetyl-L-cysteine (NAC) is derived from cysteine and is a popular dietary supplement that is metabolized into the antioxidant glutathione.
Cysteine - Biochemistry.
Cysteine contains a highly nucleophilic thiol group, and one of its primar ...
The chemical compound n-butyllithium is the most prominent organolithium reagent. It has wide use as a polymer initiator in the production of thermoplastic elastomers (TPE) such as styrene. Also it is a strong base in organic synthesis. As it reacts violently with air and water, it is rarely used in pure form.
N-Butyllithium - History and market.
Annual worldwide production and consumption of butyllithium and other organolithium compounds is estimated at 1800 metric tonnes.
N-Butyllith ...
An ushanka (уша́нка) [oo-shah-n-kah] is a Russian fur cap with ear flaps that can be tied up to the crown of the cap, which is often made of fur, or tied at the chin to protect the ears from the cold.
Though ushankas are a distinctly Russian hat, indeed, the stereotypical Russian is seen to wear one, the wearing of fur caps of similar design is common throughout China, North Korea, Eastern Europe and the former Soviet Union. It is possible that Russians adopted this design from Mongols du ...
Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP, most notably by activating intracellular protein kinases in response to the binding of membrane-impermeable peptide hormones to the external cell surface.
Cyclic guanosine monophosphate - Synthesis.
cGMP synthesis is catalyzed by guanylate cyclase (GC) which converts GTP to cGMP. Membrane-bound GC is activated by peptide hormones such as the nat ...
Dimethyl Sulfoxide (DMSO, empirically C2H6OS), also known as methyl sulfoxide, dimethyl sulphoxide, dimethylsulfoxide, methylsulfinylmethane or sulfinylbismethane, is a sulfur-containing organic compound. It is a clear, colorless hygroscopic liquid. When it is pure it has little odor, but impure samples smell strongly of dimethyl sulfide. DMSO belongs to the class of "dipolar aprotic solvents" which includes also dimethylformamide, dimethylacetamide and N-methyl-2-pyrrolidone. It is readily soluble into a ...
Boric acid, also called boracic acid or orthoboric acid, is a mild acid often used as an antiseptic, insecticide, flame retardant, and as a precursor of other chemical compounds. It exists in the form of colorless crystals or a white powder and dissolves in water. It has the chemical formula H3BO3, sometimes written B(OH)3.
Boric acid - Preparation.
Boric acid is produced mainly from borate minerals by the reaction with sulfuric acid. The largest source of bora ...
Arginine (Arg) is an α-amino acid. The L-form is one of the 20 most common natural amino acids. In mammals, arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual.
Arginine - Structure.
Arginine can be considered to be an amphipathic amino acid as the part of the side chain nearest to the backbone is long, carbon-containing and hydrophobic, whereas the end of the side chain is a complex Including:
Acid-base reaction theories
pH
Self-ionization of water
Buffer solutions
Systematic naming
Redox reactions
Electrochemistry
Acids:
Strong acids
Weak acids
Bases:
Strong bases
Weak bases
Buffer solutions are solutions which resist change in pH upon addition of small amounts of acid or base. As a consequence of this definition, the theory of buffer solutions presented in this article uses the Arrhenius and B ...
Carbonic acid is a carbon-containing acid with the formula H2CO3. It is also a name sometimes given to solutions of carbon dioxide in water, which contain small amounts of H2CO3. The salts of carbonic acids are called bicarbonates (or hydrogencarbonates) and carbonates.
Carbon dioxide dissolved in water is in equilibrium with carbonic acid:
CO2 + H2 ...
Acid-base reaction theories
pH
Self-ionization of water
Buffer solutions
Systematic naming
Redox reactions
Electrochemistry
Acids:
Strong acids
Weak acids
Bases:
Strong bases
Weak bases
In chemistry, a weak base is a chemical base that does not ionize fully in an aqueous solution. As bases are proton acceptors, a weak base may also be defined as a chemical base in which protonation is incomplete. This resu ...
In general usage, alcohol (from Arabic al-kukhul الكحول, al meaning 'the' and kukhul meaning 'spirit', the chemical) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). This sense underlies the term alcoholism (addiction to alcohol). Other forms of alcohol are usually described with a clarifying adjective, as in isopropyl alcohol or by the suffix -ol, as in isopropanol.
As a drug, com ...
Acid-base reaction theories
pH
Self-ionization of water
Buffer solutions
Systematic naming
Redox reactions
Electrochemistry
Acids:
Strong acids
Weak acids
Bases:
Strong bases
Weak bases
For the cyber novellete by Nadeem Parachee, see Acidity (Novelette).
An acid (from Arabic Azait meaning oil, often represented by the generic formula AH) ...
