Search results
Results from the WOW.Com Content Network
Collision frequency describes the rate of collisions between two atomic or molecular species in a given volume, per unit time. In an ideal gas , assuming that the species behave like hard spheres, the collision frequency between entities of species A and species B is: [ 1 ]
For a diluted solution in the gas or the liquid phase, the collision equation developed for neat gas is not suitable when diffusion takes control of the collision frequency, i.e., the direct collision between the two molecules no longer dominates. For any given molecule A, it has to collide with a lot of solvent molecules, let's say molecule C ...
is the momentum-transfer collision frequency, m {\displaystyle m} is the mass. Mobility is related to the species' diffusion coefficient D {\displaystyle D} through an exact (thermodynamically required) equation known as the Einstein relation : μ = q k T D , {\displaystyle \mu ={\frac {q}{kT}}D,} where
The collision cross section per volume or collision cross section density is ... The equation above presupposes that the gas density is low (i.e. the pressure is low
The plasma collisionality is defined as [4] [5] =, where denotes the electron-ion collision frequency, is the major radius of the plasma, is the inverse aspect-ratio, and is the safety factor. The plasma parameters m i {\displaystyle m_{\mathrm {i} }} and T i {\displaystyle T_{\mathrm {i} }} denote, respectively, the mass and temperature of the ...
Also called the probability factor, the steric factor is defined as the ratio between the experimental value of the rate constant and the one predicted by collision theory. It can also be defined as the ratio between the pre-exponential factor and the collision frequency , and it is most often less than unity.
In chemical kinetics, the pre-exponential factor or A factor is the pre-exponential constant in the Arrhenius equation (equation shown below), an empirical relationship between temperature and rate coefficient. It is usually designated by A when determined from experiment, while Z is usually left for collision frequency. The pre-exponential ...
The polar angle is distributed according to the probability density, = Using the change of variable = , we have () = so = = = The post-collision velocities are set as = + = Note that by conservation of linear momentum and energy the center of mass velocity and the relative speed are unchanged in a collision.