Search results
Results from the WOW.Com Content Network
The donor number is a measure of the ability of a solvent to solvate cations and Lewis acids. The method was developed by V. Gutmann in 1976. [2] Likewise Lewis acids are characterized by acceptor numbers (AN, see Gutmann–Beckett method). Typical solvent values are: [3] acetonitrile 14.1 kcal/mol (59.0 kJ/mol) acetone 17 kcal/mol (71 kJ/mol)
Mulliken charges arise from the Mulliken population analysis [1] [2] and provide a means of estimating partial atomic charges from calculations carried out by the methods of computational chemistry, particularly those based on the linear combination of atomic orbitals molecular orbital method, and are routinely used as variables in linear regression (QSAR [3]) procedures. [4]
The aggregation number of micelles can be determined by isothermal titration calorimetry when the aggregation number is not too high. [2] [3] Another classical experiment to determine the mean aggregation number would involve the use of a luminescent probe, a quencher and a known concentration of surfactant. If the concentration of the quencher ...
The Damköhler numbers (Da) are dimensionless numbers used in chemical engineering to relate the chemical reaction timescale (reaction rate) to the transport phenomena rate occurring in a system. It is named after German chemist Gerhard Damköhler , who worked in chemical engineering, thermodynamics, and fluid dynamics. [ 1 ]
For hydrocarbons, the DBE (or IHD) tells us the number of rings and/or extra bonds in a non-saturated structure, which equals the number of hydrogen pairs that are required to make the structure saturated, simply because joining two elements to form a ring or adding one extra bond (e.g., a single bond changed to a double bond) in a structure reduces the need for two H's.
One formulation is that if journals in a field are sorted by number of articles into three groups, each with about one-third of all articles, then the number of journals in each group will be proportional to 1:n:n 2. [1] There are a number of related formulations of the principle. In many disciplines, this pattern is called a Pareto distribution.
The Beilstein database is a database in the field of organic chemistry, in which compounds are uniquely identified by their Beilstein Registry Number.The database covers the scientific literature from 1771 to the present and contains experimentally validated information on millions of chemical reactions and substances from original scientific publications.
In number theory, a deficient number or defective number is a positive integer n for which the sum of divisors of n is less than 2n. Equivalently, it is a number for which the sum of proper divisors (or aliquot sum ) is less than n .