Department of Earth Science |Northeastern Illinois University

AQUEOUS GEOCHEMISTRY
ESCI 406
Spring, 2005
Homework #5: Due Monday, April 11, 2005                                                                     Sanders

Portfolio of Analyses

* The objective of this assignment is to calculate the carbonate species concentrations for an analysis set.  In this assignment, you will take one of your analysis sets and choose 3-5 analyses from it.  For each analysis, you will calculate the values of all of the carbonate species, even though they were not all included in the original analysis.  In your work, include a determination of whether or not a given sample is in equilibrium with calcite, or not.  If it is not, tell whether it is under or over saturated with respect to calcite.

This homework assignment will form the third entry in your Portfolio of Analyses.  Please hand it in with the whole portfolio.  I will look at and potentially comment on the whole portfolio, but only this week's assignment will be graded.

The Assignment Cover page: Create a cover page for this section. Introduction: Describe the basic principles and equilibria within the carbonate system. Methods: Explain how you calculated the values of the various carbonate species and determined whether or not the sample is at equilibrium with respect to calcite.  Be sure to use the Debye-Huckel model for estimating and using activity coefficients. Results: Summarize your results in a neat table. Discussion: Discuss what the results showed.  Be sure to put the results in the geologic context.

Things to Check Before Handing in the Portfolio

* Cite the source of every piece of information that is not taken from your own brain.  Use standard citation format!  (e.g. "Eby, 2005")
* Check your "References Cited" page, and make sure it includes all of the sources you have cited thus far, in proper format. 
* Make any corrections to previous versions of the portfolio (based on my comments on previous assignments, or your own edits/corrections.
* Hand in the whole portfolio with all the components listed here:
    - cover page
    - the current assignment, including its cover page
    - the cover pages for each of the previous assignments
    - the previous assignments
    - cover page for each analysis set
    - five analysis sets
    - References Cited
* Use dividers, tabs, or colored pages between sections.

© 2005 Laura L. Sanders.  Last updated April 4, 2005.