Discussion Questions: High-Sulfur Coal and Acidic Water
General Level (Grades 6-12)
Heavy metal ions dissolve well in water contaminated by acid mine drainage. How do heavy metals such as chromium (Cr), arsenic (As), lead (Pb), iron (Fe), and mercury (Hg) affect the health of mammals? (Note to teacher: This topic would also make a research subject for students.)
Intermediate Level (Grades 9-12)
Explain what is meant by a logarithmic scale. How will the concentration of hydrogen ions (H+) in water with a pH of 6 compare to the concentration of hydrogen ions in what with a pH of 7? What effect will this have on the relative acidity of the water?
Would the oxidation of sulfur be faster in larger pyrite chunks or smaller pyrite chunks? Explain how particle size may affect reaction rates.
Advanced Level (High School Chemistry)
The effects of acid mine drainage may vary drastically between dry and wet seasons. If a stream with AMD contamination undergoes considerable evaporation, explain how this will affect the pH of the stream. Will this affect the precipitation of Fe(OH)3 (assuming adequate limestone is present)? If so, explain how. Explain how temperature changes could affect the precipitation of Fe(OH)3.
Using the following equilibrium expression (Le Châtelier's Principle), explain the effects of pH on the solubility of