| Hydroquinone | |
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| IUPAC name | Hydroquinone |
| Other names | Quinol Benzene-1,4-diol |
| Identifiers | |
| CAS number | [123-31-9] |
| RTECS number | MX3500000 |
| SMILES | Oc1ccc(O)cc1 |
| Properties | |
| Molecular formula | C6H4(OH)2 |
| Molar mass | 110. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 1 g/mol |
| Appearance | white solid |
| Density | 1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 3 g/cm3, solid |
| Melting point |
172 °C |
| Boiling point |
287 °C |
| Solubility in water | 5. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. 9 g/100 ml (15 °C) |
| Structure | |
| Dipole moment | zero |
| Hazards | |
| EU classification | Harmful (Xn) Carc. Cat. 3 Muta. Cat. 3 Dangerous for the environment (N) |
| NFPA 704 |
 1
2
0
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| R-phrases | R22, R40, R41, R43, R50, R68 |
| S-phrases | (S2), S26, S36/37/39, S61 |
| Flash point | 165 °C |
| Related compounds | |
| Related benzenediols | Pyrocatechol Resorcinol |
| Related compounds | 1,4-benzoquinone |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Hydroquinone, also benzene-1,4-diol or quinol, is an aromatic organic compound which is a type of phenol, having the chemical formula C6H4(OH)2. In physics there are two kinds of dipoles ( Hellènic: di(s- = two- and pòla = pivot hinge An electric dipole is a Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation In Biology, a mutagen ( Latin, literally origin of change) is a physical or chemical agent that changes the genetic information (usually DNA) Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air Benzenediols or dihydroxybenzenes are Aromatic Chemical compounds and Polyphenols in which two Hydroxyl groups are substituted onto a Pyrocatechol, more commonly known as catechol, is the Organic compound with the formula C6H4(OH2 Resorcinol (or resorcin) is a Chemical compound from the dihydroxy Phenols it is the 13- Isomer of Benzenediol. In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. In Organic chemistry, phenols, sometimes called phenolics, are a class of Chemical compounds consisting of a Hydroxyl group (- A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Its chemical structure, shown in the table at right, has two hydroxyl groups bonded to a benzene ring in a para position. Chemical structure refers to Molecular geometry, Electronic structure and Crystal structure. Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 It is a white granular solid at room temperature and pressure. A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface
Contents |
Nomenclature
Hydroquinone is the name recommended by the International Union of Pure and Applied Chemistry (IUPAC) in its 1993 Recommendations for the Nomenclature of Organic Chemistry [1]
Properties
Hydroquinone can undergo mild oxidation to convert to the compound parabenzoquinone, C6H4O2, often called p-quinone or simply quinone. The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state "DDQ" redirects here DDQ is also the former callsign of a TV station in Toowoomba Queensland Australia Reduction of quinone reverses this reaction back to hydroquinone. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Some biochemical compounds in nature have this sort of hydroquinone or quinone section in their structures, such as Coenzyme Q, and can undergo similar redox interconversions. Coenzyme Q10 (also known as ubiquinone ubidecarenone coenzyme Q and abbreviated at times to CoQ10 CoQ Q10 or Q is a Benzoquinone, where Q Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state
The hydroxyl groups of hydroquinone are quite weakly acidic. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Hydroquinone can lose an H+ from one of the hydroxyls to form a monophenolate ion or lose an H+ from both to form a diphenolate ion.
Uses
Hydroquinone has a variety of uses principally associated with its action as a reducing agent which is soluble in water. A reducing agent (also called a reductant or reducer) is the element or a compound in a Redox (reduction-oxidation reaction (see Electrochemistry Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. It is a major component in most photographic developers where, with the compound Metol, it reduces silver halides to elemental silver. In Film developing, photographic developer (or just developer) is a chemical that makes the Latent image on the film or print visible Metol is a developing agent used in b&w Photographic developers In its pure form it is a Solid rather light-sensitive Chemical which is the half A halide is a Binary compound, of which one part is a Halogen Atom and the other part is an element or radical that is less Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen
In human medicine, hydroquinone is used as a topical application in skin whitening to reduce the color of skin as it does not have the same predisposition to cause dermatitis as Metol does. The term skin whitening covers a variety of cosmetic methods used to whiten the Skin. Dermatitis is a Blanket term meaning any " Inflammation of the skin" (e This use is banned in some countries (e. g. France) because of fears of a cancer risk. This article is about the country For a topic outline on this subject see List of basic France topics. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled
The disodium diphenolate salt of hydroquinone is used as an alternating comonomer unit in the production of the polymer PEEK. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants A monomer (from Greek mono "one" and meros "part" is a small Molecule that may become chemically bonded to other A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Chemical resistance PEEK also exhibits good chemical resistance in many environments including Alkalis
As a polymerization inhibitor, hydroquinone prevents polymerization of acrylic acid, methyl methacrylate, etc.
It is also used as a raw material of herbicides, rubber antioxidants and dye stuffs.
Natural occurrences
Hydroquinones are one of the two primary reagents in the defensive glands of bombardier beetles, along with hydrogen peroxide (and perhaps other chemicals, depending on the species), which collect in a reservoir. Bombardier Beetles are Ground beetles ( Carabidae) in the tribes Brachinini, Paussini, Ozaenini, or Metriini —more Hydrogen peroxide (H2O2 is a very pale blue liquid which appears colorless in a dilute solution slightly more Viscous than water The reservoir opens through a muscle-controlled valve onto a thick-walled reaction chamber. This chamber is lined with cells that secrete catalases and peroxidases. Catalase is a common Enzyme found in nearly all living organisms where it functions to catalyze the decomposition of Hydrogen peroxide to Peroxidases ( EC number 1111x are a large family of Enzymes A majority of peroxidase protein sequences can be found in the PeroxiBase database When the contents of the reservoir are forced into the reaction chamber, the catalases and peroxidases rapidly break down the hydrogen peroxide and catalyze the oxidation of the hydroquinones into p-quinones. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state "DDQ" redirects here DDQ is also the former callsign of a TV station in Toowoomba Queensland Australia These reactions release free oxygen and generate enough heat to bring the mixture to the boiling point and vaporize about a fifth of it, producing a hot spray from the beetle's abdomen. In Vertebrates such as Mammals the abdomen (belly constitutes the part of the body between the Thorax (chest and Pelvis.
See also
References
- ^ Panico, R. Pyrocatechol, more commonly known as catechol, is the Organic compound with the formula C6H4(OH2 Resorcinol (or resorcin) is a Chemical compound from the dihydroxy Phenols it is the 13- Isomer of Benzenediol. In Film developing, photographic developer (or just developer) is a chemical that makes the Latent image on the film or print visible ; & Powell, W. H. (Eds. ) (1994). A Guide to IUPAC Nomenclature of Organic Compounds 1993. Oxford: Blackwell Science. ISBN 0-632-03488-2.
External links
- International Chemical Safety Card 0166
- NIOSH Pocket Guide to Chemical Hazards
- IARC Monograph: "Hydroquinone"
- European Chemicals Bureau
- IUPAC Nomenclature of Organic Chemistry (online version of the "Blue Book")
Dictionary
hydroquinone
-noun
- (organic chemistry) The diphenol para-dihydroxy benzene, used as a mild reducing agent in photographic developing; isomeric with catechol and resorcinol.
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