Tags
A tag is a keyword or label that categorizes your question with other, similar questions.
Use this tag for questions relating to organic molecules and their properties (structure of organic molecules, spectroscopic properties, reaction mechanisms, stereochemistry etc). DO NOT use this tag as the only tag in your question, as this tag by itself cannot appropriately classify your question. Always use this tag in addition to other more specific tags.
10359 questions
Inorganic compounds generally do not have C-H bonds, while organic compounds do have such bonds. The distinction between inorganic and organic chemistry, however, is far from absolute.
4907 questions
The study of chemical systems using the laws and concepts of physics. This usually requires the techniques of thermodynamics, statistical mechanics and quantum mechanics.
4808 questions
This tag should be applied to questions concerning acid and base reactions. An acid is capable of donating a hydron/ proton (Brønsted acid) or capable of forming a covalent bond with an electron pair (Lewis acid). A base on the other hand is a chemical species/ molecular entity having an available pair of electrons capable of forming a covalent bond with a hydron/ proton (Brønsted base) or with the vacant orbital of some other species (Lewis base).
3189 questions
The detailed (and as complete as possible) description of plausible or observable pathways leading from reactants to products of a chemical process. This tag should be applied to questions about these processes. It may be applied to hypothetical and/or proposed mechanisms.
2896 questions
Applicable to questions about heat, energy, work, and their interconversion in chemistry. See the tag wiki for a detailed list of topics. Questions tagged may also be tagged with [enthalpy], [energy], [free-energy] where appropriate.
2839 questions
The branch of chemistry that deals with the study of redox reactions and how they can be applied to generate electricity (in electrochemical cells) and to carry out non-spontaneous reactions using electricity (electrolysis).
1882 questions
This tag should be applied to questions relating to the theory, design, techniques or performance of chemical experiments. This includes but is not limited to theoretical structures, expected products, thermal calculations, and empirical analysis. Additional tags should be applied to narrow down the field of research.
1760 questions
Applications of chemistry to reagents, reactions and processes of everyday life. Use this tag for question on chemistry in an out-of-laboratory/class context. DO NOT use this tag merely because the question is about simple chemistry.
1756 questions
The state in which both reactants and products are present at concentrations which have no further tendency to change with time.
1713 questions
Quantum chemistry is a subfield of quantum mechanics. Like its parent field, quantum chemistry focuses on understanding physical phenomena occuring at the atomic scale. Quantum chemistry however is more focused on providing useful descriptions of electronic structure to aid in understanding chemical problems (e.g. reactions, spectra, dynamics, ...).
1555 questions
Redox is the portmanteau of reduction and oxidation. This tag should be used in questions where both the reduction and the oxidation process are under focus. This tag is not limited to inorganic chemistry. If the question is specifically about either reduction or oxidation (not both) of an organic compound, use [organic-reduction] or [organic-oxidation] instead.
1521 questions
For questions about chemical bonds (ionic/covalent/etc.), their properties (length, energy, angle, etc.) or their relation to other molecular properties (intermolecular forces/dipole moment/etc.). Do not confuse this tag with [lewis-structures], [dipole], [intermolecular-forces], etc.
1442 questions
For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.
1255 questions
This tag should be used for questions about the naming of compounds and elements, usually using systematic names according to IUPAC recommendations, but also using retained traditional names.
1156 questions
A field which employs computers to model and study chemical systems and chemical behavior, using various models, from approximations of the Schrödinger equation to Monte-Carlo simulations, to modeling with differential equations.
1125 questions
The branch of chemistry concerned with identifying and quantifying the chemical constituents of matter.
1098 questions
For questions relating to water (H₂O), specifically its structure, properties, and uses in chemistry. For questions not about water but rather about solutions in water, use tags [aqueous-solution] or [solubility] instead.
1096 questions
This tag is for questions concerning biochemical methods (e.g. electrophoresis) or those concerning biochemical mechanisms or research. Do not use this tag if your question is merely about compounds often used in areas related to biochemistry or associated with these. These may fall under organic chemistry or the appropriate compound’s functional groups’ tags.
1075 questions
For questions related to the solubility of compounds in various solvents, especially in water. Do not confuse with [solutions] or [aqueous-solution].
1065 questions
This tag should be applied to questions dealing with solutions of any kind. A solution is a liquid or solid phase containing more than one substance where, for convenience, one (or more) substance(s) called the solvent is treated differently from the other substances, which are called solutes. If water is the solvent, then the more appropriate 'aqueous-solution' tag should (also) be specified.
1012 questions
For questions about the properties and reactions of aromatic compounds. This tag should also be applied to antiaromatic compounds. This tag should not be applied to general questions about resonance, use the [resonance] tag instead.
976 questions
pH (or the potential of hydrogen) is a scale used to measure how acidic or basic an aqueous solution is.
935 questions
This tag is for questions concerning coordination compounds including but not limited to ligand properties, metal properties, orbital splitting, micro- and macroscopic properties of entire complexes etc. For complexes where carbon monoxide is the only ligand, use the [carbonyl-complexes] tag instead. For organic catalysts or proteins, the tag is applicable if the question is about the metal’s direct coordination sphere.
854 questions
Applicable to questions about the spatial arrangement of atoms in a molecule and how they affect its physical or chemical properties.
839 questions
Synthesis is a purposeful execution of chemical reactions to obtain the desired product.
Applies to long and complex natural product syntheses as much as to short one or two-step syntheses. This also covers synthetic problem sets and retrosynthetic analyses.
832 questions
This tag should be applied to questions that deal with the particular arrangement of atoms in a molecule, the so-called molecular structure or geometry.
776 questions
Use this tag for questions about spectroscopic methods in practice and in theory, especially where more specific tags for the individual method (such as [nmr-spectroscopy] or [ir-spectroscopy]) are not available.
770 questions
The concentration characterizes the composition of a mixture with respect to the volume of the mixture. There are mass, amount, number and volume concentrations. Related and within the scope of this tag are normality, molality, mole fraction/ratio, mass fraction/ratio.
760 questions
Use of molecular orbital (MO) theory allows for an understanding of the observed properties (shape, reactivity) of molecules. The tag should be applied to all questions related to MO theory, from questions about the qualitative use of the theory to questions about the underlying quantum mechanics and applications in computational chemistry.
754 questions
Physical and chemical laws describing the properties and behavior of gases. This tag currently applies to properties and laws concerning both ideal and real gases.
741 questions
For questions about compounds containing the carbonyl group, C=O, the carboxylic acid group (-COOH), or its derivatives (anhydrides/esters/amides/acid halides). For questions about complexes involving carbon monoxide as a ligand use [carbonyl-complexes] instead.
720 questions
For questions relating to the energy required for or produced by reactions, including questions of endothermicity/exothermicity, bond enthalpy, etc.
713 questions
Stoichiometry refers to the relationship between the amounts of substances of the reactants and the amount of substances of the formed products. This tag should be used for specific questions about chemical reaction equations.
671 questions
Electrons are subatomic particles with the symbol e−. They have a negative electric charge (-1 elementary charge. )
648 questions