Message Boards Message Boards

0
|
1831 Views
|
1 Reply
|
0 Total Likes
View groups...
Share
Share this post:

Result change when variable has index in WA (modeling chemical equilibrium)

Dear community, I entered some equations related to chemical equilibrium. I entered the input once with an index to one of the variables ("a_1") and once without the indices (just "a"). The result produced by Wolfram Alpha is completely different. Here are the two inputs to the solver:

10^-2.16=bh/a, 10^-7.21=ch/b, 10^-12.32=dh/c, a+b+c+d=1, 10^-14=oh

and

10^-2.16=bh/a1, 10^-7.21=ch/b, 10^-12.32=dh/c, a1+b+c+d=1, 10^-14=oh

Furthermore the result changes everytime I add an index to another variable ("b_1" instead of "b",...). Does anybody know the reason and can point me towards a valid solution?

Thank you very much! Andreas

P.S.: My project is chemistry-related. I want to model the course of the concentrations of all species during the titration of phosphoric acid with sodium hydroxide. The Input above models the first step, where no sodium hydroxide.

POSTED BY: Andreas Uhe
Posted 6 months ago

i too have wondered if it would be worth the effort to use mathematica for chemistry titrations and equlibria analysis. Most of us were trained to do this with spreadsheet programs

Can you be more specific on the chemistry and algebra here? I see the "mass action" with a.b.c.d and the partial fractions. but not quite following what you are trying to do

POSTED BY: Roger Wells
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Reply Preview
Attachments
Remove
or Discard

Group Abstract Group Abstract