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[carbon60]

Hello all,

It has been two years since I took my Thermo classes so I am trying to brush up on how to perform equilibrium calculations on a system involving multiple reactions in the liquid phase, using the extent of reaction method, before I enter the workforce.

I have decided that good practice would be to try to model the neutralization of HCl by NaOH. I attempted to calculated the ending composition and compared the resulted to what ChemCad simulated. The attached PDF covers my approach, while the excel shows the calculations and what Chemcad got.

The problem is I am completely stuck and I don't know what is going wrong. For this specific system I could not get the solver in excel to get good results. However, I tried modeling the disassociation of HF, where excel correctly solved for the K values, and my hand calculations where still completely off making me worry that my approach is wrong.

I guess I have four questions that I am hoping someone can answer for me

1) Is there something wrong with my approach to solving these types of problems, if so I would be grateful for any guidance.

2) Should I instead be using a minimization of total Gibbs method?

3)How do you normally use excel to solve for systems with multiple extents of reactions. I attempted to minimize the SSE but that did not produce K calculated values even close to the actual values.

4) does anyone know a good resource that has good examples for L-L E and L-LS E my thermo book focuses mainly on gas phase

Thank you in advance for any help or guidance you can give me. I know that it takes some effort to help people so I am very grateful for your time and help.

Attached Files

•  NaOH-Hcl Neutralization (CHE Resources).xlsx   38.82KB   17 downloads
•  CHE Resources question.pdf   273.32KB   12 downloads