rate constants


Also found in: Encyclopedia.

rate con·stants (k),

proportionality constants equal to the initial rate of a reaction divided by the concentration of the reactant(s); for example, in the reaction A → B + C, the rate of the reaction equals -d[A]/dt = k1[A]. The rate constant k1 is a unimolecular rate constant because only one molecular species is reacting and has units of reciprocal time (for example, s-1). For the reverse reaction, B + C → A, the rate equals -d[B]/dt = d[A]/dt = k2[B][C]. The rate constant k2 is a bimolecular rate constant and has units of reciprocal concentration-time (for example, M-1 s-1).
Synonym(s): velocity constants

rate con·stants

(k) (rāt kon'stănts)
Proportionality constants equal to the initial rate of a reaction divided by the concentration of the reactant(s); e.g., in the reaction A → B + C, the rate of the reaction equals -d[A]/dt = k1[A]. The rate constant k1 is a unimolecular rate constant, since there is only one molecular species reacting, and has units of reciprocal time (e.g., sec-1). For the reverse reaction, B + C → A, the rate equals -d[B]/dt = d[A]/dt = k2[B][C]. The rate constant k2 is a bimolecular rate constant and has units of reciprocal concentration-time (e.g., m-1 sec-1).
References in periodicals archive ?
Simulation of experimental CV's can then be carried out with the calculated rate constants to verify the veracity of OHN equation.
The pseudo first-order rate constant K 1, amount of PNP adsorbed at equilibrium q e and correlation coefficients are shown in Table 3.
The most important outcomes of simulations are time curves of (RA) binding and the coefficients of exponential fit, which represent the observed rate constants and the specific binding at equilibrium.
Sw and Sm are substrates in aqueous and micellar pseudo phase respectable; K'w and K'm are the related first order rate constants and Ks is the binding constant (Domingos et al.
Parameters, including rate constants related to nucleation, formation, and dissociation of embryo as well as the Avrami Constant, could be extracted from the model.
12) Two parameters, defined as the damage rate constant and the damage exponent, determined the evolution law of fretting wear damage.
The correlation between reaction rate constants and activation energy can be obtained using Arrhenius equation.
The apparent first order rate constants decreased with an increasing initial concentration of the pyridine, indicating a non-elementary nature of the sonochemical and photochemical reactions.
The soil properties related to the rate constants of Cu release from 14 calcareous soils were also analysed.
Filling a gap in the rapidly growing field of computational chemistry, chemists from around the world offer a reference on predicting rate constants of thermal reactions, providing both selected computational methods currently in use and some successful examples.
The parameters in the system are then identified readily, which are two rate constants, [[alpha].