1. What is the chemical formula for Gypsum (Anhydrite)?
  2. What is the chemical formula for Magnetite?
  3. What is the chemical formula for Aragonite?
  4. What is the chemical formula for Calcite?
  5. Give 2 examples of undissolved organic water contaminants
    • Microorganisms:
    • 1. E. coli
    • 2. 'Beaver Fever' - Giardia
  6. SAR
    • Sodium Adsorption Ratio (a water quality parameter for agriculture)
    • Image Upload 1
  7. Water from typically from petroleum reservoirs that is extremely high in TDS
    connate water
  8. Which would likely have higher TDS, connate water or boiler feed water?
    Connate water has higher TDS
  9. Equivalent weight of CaCO3
    50.0 mg CaCO3/meq
  10. Formula for Dolomite
  11. A good SAR ratio is...
    • SAR<3 (no restrictions on crops)
    • Lower is better
  12. Permanent hardness =
    Total Hardness - Temporary Hardness
  13. For ENVS348, a water analysis is considered valid if the % Difference of the ion balance is
    Less than 10%
  14. Which is harder to remove with acid?
    Scale deposited quickly
    Scale deposited slowly
    Slow deposits of scale are typically harder to remove with acid
  15. LSI
    Langelier Scaling Index
  16. Precipitates which form elsewhere and then are carried over and deposited
    Mixed Deposits
  17. Precipitates which form directly on the pipe and are often hard and glassy
  18. LSI>0 means
    The water is supersaturated and scale is likely to form
  19. LSI=0 means
    The water is saturated
  20. LSI<0 means
    • The water is undersaturated
    • Scale may dissolve
  21. Two general schemes for removing scale
    • 1. Chemically (Soluble scales, use water, acid, EDTA)
    • 2. Mechanically (Insoluble scales)
  22. Scaling Index (Scaling Tendency) in thermodynamic terms
    Image Upload 2
Card Set
Review for midterm: various terms relating to scale