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Development of a Real-Time Dynamic Graphing Web Page |  |
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Development of a Real-Time Dynamic Graphing Web Page | |
Implementation of the Theory as Code
In summary, there are two key equations relating changes in concentrations of A and B to their concentrations at any given time:
In addition, there are two equations relating k1 and k2 to K:
Finally, a measure of whether or not equilibrium has been reached is determined by measuring Q and comparing that value to K.
That pretty much defines our variables.
| JavaScipt | Theory | Meaning |
|---|---|---|
delay | -- | the time delay between iterations |
tmax | -- | the maximum time to allow for equilibration |
t | t | the time |
r | r | a constant related to how fast equilibrium will be reached |
A | [A] | the concentration of A |
B | [B] | the concentration of B |
dA | D[A] | the change in concentration of A |
dB | D[B] | the change in concentration of B |
k1 | k1 | the forward rate constant |
k2 | k2 | the reverse rate constant |
K | K | the equilibrium constant |
Q | Q | the reaction quotient |
Our key routine is the one that will change the concentrations of A and B. Let's call it react().
These variables are global variables, because we have not placed var in front of their definitions. That's OK,
because they are variables that mean something in our theory. Let's make plotpoint() simply display on the
document status bar for now:
In addition, we need to initialize these variables:
This is all we need for a perfectly fine JavaScript program that at least displays information on the status bar.
After you click on the "Run initialize();react()" link, above, consider what might be still needed. For example, how could we stop or interrupt the process if we needed to? If you like, go ahead and change the functions in the text area, then click on the "Run" link again and see what happens. When you are ready, go on to the next page.
back to the list of examplescopyright 2001 Robert M. Hanson. All rights reserved. divgraph.js is freely distributable for noncomercial purposes, provided reference is made as "divgraph.js was developed at St. Olaf College by Robert M. Hanson (http://www.stolaf.edu/people/hansonr/divgraph)." Commercial licensing is available for specific purposes.