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Rate how strongly you agree or disagree with the following statement: “I feel prepared to explain how chemical composition of organic and inorganic components of soil and water bodies influence chemical processes therein”

You are evaluating a radiograph like the one shown in the image below for mAs and kVp.  The radiograph appears overall too dark.  The anatomy of interest appears to be adequately penetrated by the x-rays.  The radiographic density of the air on the radiograph appears dark gray but not black.   Which of the following adjustments should you make to improve this radiograph?

The below questions are bonus feedback questions Did you have enough time to complete this exam?

Do you have any other feedback for this course?

Rate how strongly you agree or disagree with the following statement: “I feel prepared to recommend appropriate techniques for analyzing specific chemical properties of soils and natural water bodies”

A solution contains {M} M (mol/L) of CaSO4 and has an overall ionic strength of {I} mol/L. What is the activity of Ca2+ in this solution? Use the Debye-Hückel limiting law and round your answer to 3 decimal places. (Note: D2L may generate unrealistic numbers since everything is randomized)

If an organic compound’s measured Kd is {Kd} when adsorbing to a soil containing {C}% organic carbon, what is the Koc of the compound? Round your answer to the nearest whole integer.

Rate how strongly you agree or disagree with the following statement: “I feel prepared to predict relative availability and mobility of contaminants and nutrients in soil based on the properties of the soil and contaminant or nutrient”

When are reduction reactions favored? (assume C is being oxidized, and some other element is being reduced)

Isotherms showing sorption of NH4+ to 3 different biochars at constant pH were fit with the Langmuir and Freundlich models. The fitted model parameters are shown below.  Freundlich Langmuir biochar  Pyrolysis temperature KF n r2 Smax KL r2 CS4s 400°C 0.418 0.280 0.955 0.954 0.554 0.959 CS5s 500°C 0.110 0.610 0.966 1.048 0.079 0.975 CS6s 600°C 0.077 0.534 0.949 0.556 0.096  0.929 Using the data, match the biochar with its properties.