Over the course of soil development from parent rock to highly weathered soils, mineral weathering reactions occur that alter the surface chemistry of the soil.  Consider the weathering transformation sequence: muscovite/biotite → illite → vermiculite → smectite → kaolinite → gibbsite During the above weathering sequence, what general changes would be expected in following mineral chemical characteristics? Why? (a)  Permanent (structural) charge (b)  pH dependent (variable) charge (c)  Types of surface functional groups (d)  Cation exchange capacity (e)  Anion exchange capacity

Choose ONE of the following questions to answer. Answering both will not allow you to earn extra points.   Option 1 In addition to mineral weathering, soil pH typically declines over time in warm, moist environments. a. What effects would this have on CEC and AEC? b. Draw a diagram explaining why CEC and AEC change with a decrease in pH. Your diagram should have at least 2 parts: low vs high pH. Adding a medium pH portion is optional. c. Add diagram labels (or a description) to explain what is happening in terms of PZC and pKa. Use arrows to show if the pKa and/or PZC labels apply to just a functional group, or the whole surface.   Option 2 Explain how each of the following factors influence sorption & bioavailability of metal cations: Soil/sediment (sorbent) properties: overall PZC, functional group pKa’s, %organic matter, types of minerals (name specific types of clays, oxides and/or hydroxides) Metal (sorbate) properties: charge, hydrated radius, water exchange rate or pKh

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”

Which of the following images shown below demonstrates the correct way to place a lateral view of the canine elbow onto the screen for evaluation by your clinician? Assume that the R marker in each image is placed correctly. To answer this question, select A, B, C, or D. A.   B.   C.   D.

A water sample is found to contain Cu but no organic or inorganic ligands except OH-. Assume that only one hydrolysis species contributes significantly to the total Cu in solution.          K        log Kf Cu2++H2O⇌Cu(OH)++H+{“version”:”1.1″,”math”:”Cu2++H2O⇌Cu(OH)++H+”} 10-7.52 -7.52    If [Cutotal] = 10-{T} M and pH = {pH}, what is the concentration of free Cu2+ in the water sample?  Format answer in scientific notation and round to 3 significant figures. Place the order of magnitude (x10^y) in the “units” box with no spaces (D2L doesn’t have a separate spot for this), followed by the units. For example: x10^-4 mol/L.

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?

Match the compounds with their most likely sorption mechanisms.

Write the correct word from each parentheses in the blanks. D2L doesn’t understand type-o’s so please check your spelling or copy-paste from the parentheses for full credit. As pH increases, [H+] in solution _______ (increases/decreases) causing the acidic or basic surface functional groups to  _______ (accept/donate) H+. As a result, the charges of the surface functional groups become more _______ (positive/negative). Consequently, cation adsorption and CEC _______ (increase/decrease), whereas anion adsorption and AEC _______ (increase/decrease) with increasing pH.

Which of the following reactions are most likely to cause acidification? Select up to 3