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

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31

Subtraoting eq. 3.1.10 from eq. 3.1.11 and taking the logarithm,

k' 2[Alo
In([Yl.-[Ylt) · III k'l - k'lt. (3.1.12)

A plot of In([Yl. - [Ylt) versus

time will yield a straight line of

k'2(Alo k'2(Alo
In k' (-In 1 ). It is the
1 s ope

object of the chemioal kinetic methodology to obtain straight line plots

slope equal to k'l and intercept

in order to determine the order of reaotion and rate constants.

After the proper rate relationship and constants have been

determined, the mechanism of the prooess can be deduoed. This is

somewhat of an intuitive prooess but there are certain guidelines. For

instanoe, the conoentration dependences in the rate law establish the

speoies that are involved in the mechaniBIII of the reaotion or prooess.

Rate laws for oomplex reaotions can take on various forms. '!'be number

of additive terms in a rate law indioate the number of parallel pathways

in the mechanism. A rate law with a denominator indicate sucoessive and

reversible pathways. The most important concept is that of the rate-

l1mi ting, or rate-determining step. In sequential steps of a mechanism

this is the slowest step with the lowest valued rate constant, k. It

controls the progress of the entire reaotion since faster subsequent

steps cannot prooeed until the rate limiting step has oocurred. A final

rule is that any given mechanistio interpretation of a rate law is not

unique to that rate. Alternative meohanisms leading to a given rate law

are kinetically indistinguishable and oannot be ruled out.

Chemical reactions and physical prooesses often display a

temperature dependenoe. TYpically the rate constant is logarithmically

dependent on the inverse of temperature. Three theories have made use