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Dibromophenol
Dibromophenols are a group of bromophenols consisting of one hydroxy group and two bromine atoms bonded to a benzene ring. There are six structural isomers, each with the molecular formula C6H4Br2O, which differ by arrangement of the substituents. References {{reflist Bromobenzene derivatives Phenols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromophenol
A bromophenol is an organic compound consisting of hydroxyl groups and bromine atoms bonded to a benzene ring. They may be viewed as hydroxyl derivatives of bromobenzene, or as brominated derivatives of phenol. There are five basic types of bromophenols (mono- to pentabromophenol) and 19 different bromophenols in total when positional isomerism is taken into account. Bromophenols are produced by electrophilic halogenation of phenol with bromine. List of bromophenols There is a total of 19 bromophenols, corresponding to the different ways in which bromine atoms can be attached to the five carbon atoms in the benzene ring of the phenol molecule, excluding the carbon atom to which the hydroxy group is attached. Monobromrophenols have three isomers because there is only one bromine atom that can occupy one of three ring positions on the phenol molecule; 2-bromophenol, for example, is the isomer that has a bromine atom in the '' ortho'' position. Pentabromophenol, by contrast, has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,4-Dibromophenol
2,4-Dibromophenol is an isomer of dibromophenol with the molecular formula C6H4Br2O. Properties At room temperature, 2,4-dibromophenol is a solid with needle-like crystals. It melts at and boils at . it has a molecular weight of 251.905 g/mol. It is soluble in water, ethanol, ether and benzene and slightly soluble in carbon tetrachloride. Occurrence 2,4-Dibromophenol is found in certain molluscs and crustaceans, as well as the acorn worm The acorn worms or Enteropneusta are a hemichordate class of invertebrates consisting of one order of the same name. The closest non-hemichordate relatives of the Enteropneusta are the echinoderms. There are 111 known species of acorn worm in th ... '' Saccoglossus bromophenolosus'', which is named after it. References {{DEFAULTSORT:Dibromophenol, 2,4- Phenols Bromobenzene derivatives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GHS Hazard Statements
Hazard statements form part of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). They are intended to form a set of standardized phrases about the hazards of chemical substances and mixtures that can be translated into different languages. As such, they serve the same purpose as the well-known R-phrases, which they are intended to replace. Hazard statements are one of the key elements for the labelling of containers under the GHS, along with: *an identification of the product *one or more hazard pictograms (''where necessary'') *a signal word – either Danger or Warning – where necessary * precautionary statements, indicating how the product should be handled to minimize risks to the user (as well as to other people and the general environment) *the identity of the supplier (who might be a manufacturer or importer). Each hazard statement is designated a code, starting with the letter H and followed by three digits. Statements which correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GHS Hazard Pictograms
Hazard pictograms form part of the international Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Two sets of pictograms are included within the GHS: one for the labelling of containers and for workplace hazard warnings, and a second for use during the transport of dangerous goods. Either one or the other is chosen, depending on the target audience, but the two are not used together for the same hazard. The two sets of pictograms use the same symbols for the same hazards, although certain symbols are not required for transport pictograms. Transport pictograms come in a wider variety of colors and may contain additional information such as a subcategory number. Hazard pictograms are one of the key elements for the labelling of containers under the GHS, along with:Part 1, section 1.4.10.5.2, GHS Rev.2 *an identification of the product; *a signal word – either Danger or Warning – where necessary *GHS hazard statements, hazard statements, indicating the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting Point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state of matter, state from solid to liquid. At the melting point the solid and liquid phase (matter), phase exist in Thermodynamic equilibrium, equilibrium. The melting point of a substance depends on pressure and is usually specified at a Standard temperature and pressure, standard pressure such as 1 Atmosphere (unit), atmosphere or 100 Pascal (unit), kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to Supercooling, supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact, the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the #Melting point measurements, melting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical State
In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. Different states are distinguished by the ways the component particles (atoms, molecules, ions and electrons) are arranged, and how they behave collectively. In a solid, the particles are tightly packed and held in fixed positions, giving the material a definite shape and volume. In a liquid, the particles remain close together but can move past one another, allowing the substance to maintain a fixed volume while adapting to the shape of its container. In a gas, the particles are far apart and move freely, allowing the substance to expand and fill both the shape and volume of its container. Plasma is similar to a gas, but it also contains charged particles (ions and free electrons) that move independently and respond to electric and magnetic fields. Beyond the classical states of matter, a wide variety o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Mass
In chemistry, the molar mass () (sometimes called molecular weight or formula weight, but see related quantities for usage) of a chemical substance ( element or compound) is defined as the ratio between the mass () and the amount of substance (, measured in moles) of any sample of the substance: . The molar mass is a bulk, not molecular, property of a substance. The molar mass is a ''weighted'' ''average'' of many instances of the element or compound, which often vary in mass due to the presence of isotopes. Most commonly, the molar mass is computed from the standard atomic weights and is thus a terrestrial average and a function of the relative abundance of the isotopes of the constituent atoms on Earth. The molecular mass (for molecular compounds) and formula mass (for non-molecular compounds, such as ionic salts) are commonly used as synonyms of molar mass, as the numerical values are identical (for all practical purposes), differing only in units ( dalton vs. g/mol o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name since it does not contain any words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called '' empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of atoms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PubChem
PubChem is a database of Chemistry, chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information (NCBI), a component of the National Library of Medicine, which is part of the United States National Institutes of Health (NIH). PubChem can be accessed for free through a web user interface. Millions of compound structures and descriptive datasets can be freely downloaded via FTP. PubChem contains multiple substance descriptions and small molecules with fewer than 100 atoms and 1,000 bonds. More than 80 database vendors contribute to the growing PubChem database. History PubChem was released in 2004 as a component of the Molecular Libraries Program (MLP) of the NIH. As of November 2015, PubChem contains more than 150 million depositor-provided substance descriptions, 60 million unique chemical structures, and 225 million biological activity test results (from over 1 million assay experiments performe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Formula
The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are connected to one another. The chemical bonding within the molecule is also shown, either explicitly or implicitly. Unlike other chemical formula types, which have a limited number of symbols and are capable of only limited descriptive power, structural formulas provide a more complete geometric representation of the molecular structure. For example, many chemical compounds exist in different isomeric forms, which have different enantiomeric structures but the same molecular formula. There are multiple types of ways to draw these structural formulas such as: Lewis structures, condensed formulas, skeletal formulas, Newman projections, Cyclohexane conformations, Haworth projections, and Fischer projections. Several systematic chemical naming formats, as in chemical databases, are used that are equivalent to, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
