The final day of the Fall 2025 semester is December 12, 2025

The compound shown below has the following properties:     molar mass ~228 g mole-1 water solubility: 120 – 300 mg L-1 pKa1: 9.6 pKa2: 10.2 Do you expect this compound to interact strongly with positively or negatively charged sites (or neither) on mineral surfaces in most soils (at typical pH’s)? Why or why not? What kinds of soil components (organic matter, layer silicates, sesquioxides) are likely to be adsorbents for this molecule? (i.e. to what soil materials this chemical adsorb to in soil?) Why – what chemical characteristics do these soil components have that attract the above molecule?

Match the names of the Fe minerals with where you would expect to find them

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

Sort the phyllosilicate minerals in order of weathering in a typical idealized weathering sequence (1=least weathered)

If you haven’t done so already, please fill out  this survey (open in NEW TAB) on what Environmental Applications you want to learn most about in Module 7.

Match the organic matter component terms with their example chemical structures

Which concentrations or other variables will increase or decrease following flooding?

Match each simplified phyllosilicate diagram with its name

Using the logK values in the table below, calculate the logK of the summary reaction.   K log K CO2 (g) + H2O(l)   ⇄  H2CO3(aq)  3.16 x 10-2 = 10-1.5 -1.5 H2CO3 (aq)  ⇄  H+(aq) + HCO3‑(aq)  3.98 x 10-7 = 10-6.4 -6.4 HCO3‑ (aq)  ⇄  H+(aq)  + CO32‑(aq)  5.01 x 10-11 = 10-10.3  -10.3 Ca2+(aq)  + CO32‑ (aq)   ⇄  CaCO3(s)   108.3   8.3 Summary reaction: CO2(g) + H2O(l) + Ca2+(aq) ⇄  2H2+(aq) + CaCO3(s) logK of summary reaction (round to 1 decimal place): _______