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In chemistry a donor number (DN) is a quantitative measure of Lewis basicity. A donor number is defined as the negative enthalpy value for the 1:1 adduct formation between a Lewis base and the standard Lewis acid SbCl 5 ( antimony pentachloride ), in dilute solution in the noncoordinating solvent 1,2-dichloroethane with a zero DN.
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.
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. For example, the proper divisors of 8 are 1, 2, and 4, and their sum is less than 8, so 8 is deficient.
Bodenstein number: Bo or Bd = / = Max Bodenstein: chemistry (residence-time distribution; similar to the axial mass transfer Peclet number) [2] Damköhler numbers: Da = Gerhard Damköhler: chemistry (reaction time scales vs. residence time)
Once this is determined, all one needs to do is take the total value of Δ f H, subtract the Δ f H caused by the C−(C) 2 (H) 2 group(s), and then divide that number by two (due to two C−(C)(H) 3 groups), obtaining the value of the C−(C)(H) 3 group. From the knowledge of these two groups, Benson moved forward obtain and list functional ...
The practical importance of high (i.e. close to 1) transference numbers of the charge-shuttling ion (i.e. Li+ in lithium-ion batteries) is related to the fact, that in single-ion devices (such as lithium-ion batteries) electrolytes with the transfer number of the ion near 1, concentration gradients do not develop. A constant electrolyte ...
The total time for this approach is O(nm), where n is the number of vertices in the graph and m is its number of edges. For weighted graphs, one may instead use the Floyd–Warshall algorithm [ 13 ] [ 14 ] [ 15 ] or Johnson's algorithm , [ 16 ] with running time O( n 3 ) or O( nm + n 2 log n ) respectively.
The number of components represents the minimum number of independent chemical species necessary to define the composition of all phases of the system. [ 2 ] Calculating the number of components in a system is necessary when applying Gibbs' phase rule in determination of the number of degrees of freedom of a system.