WMOD00300

• Title: Characterization of Silver Iodide-Sodium Iodide Ice Nuclei Using Chemical Kinetic Methodology
• Date: 5/1/1985
• State: CO
• Weather Modification - Doc Type: Report

tAUt
k - It II exp (~) exp (---RT )
Hh R

<3.1.14)

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of this relation. First, the Arrhenius relation,

-E
k .. A exp (Rt)

<3.1.13)

is simply an empirical relationship where k is the measured rate

constant at any temperature, A is the pre-exponential faotor,

independent of temperature, Ea is the energy of activation, R is the gas
constant, and T is temperature in ltel vine A plot of ln k versus T-1

yields the interoept A and a slope equal to E IR. Second, collision
a
theory presents a similar relation for bimolecular reaotions in the gas

phase. Third, the Eyring or activated complex or absolute rate theory

expresses the rate oonstant as

where It is a transmission coetfecient, usually taken as unity, N is
Avagadro's number, h is Planok' s constant, and AS t and AH t are the

entropy and enthalpy, respeotively, of activation. The aotivated

oomplex is a hybrid speoies,usually a oombination of two moleoules, in

quasi-equilibrium with the reaotants. A plot of the Eyring relation,
In kIT versus T-1, yields a straight line with slope equal to AHt/R and
t
an intercept of ~ exp(Af') from which ASt oan be determined.
The use of one reaction energetios relation as opposed to another,

with the exception of the oollision theory which applies only to gases,
is not of oritical importance. This is because the exponential term

containing T is dominant in the relation. It is often the case that
plots of ln k and ln kIT versus T-1 are both linear within experimental