Certification Action Line features questions and answers typical of those appearing in Water Quality Association (WQA) certification examinations. Some answers may not satisfy everyone or every condition.

1. The sodium chloride content of water does not affect the ion exchange water softening process.
      a) True       b) False

2. Trivalent ions, such as aluminum (Al3+) and phosphate (PO43-), are usually insignificant in the ion exchange treatment of water.
      a) True       b) False

3. The following cations, if present in water, may limit the use of sulfuric acid as a regenerant in the deionization process.
      a) Iron and manganese
      b) Calcium and magnesium
      c) Barium and strontium
      d) All of the above

4. In water analyses, parts per million (ppm) and milligrams per liter (mg/L) are used interchangeably because one liter of water weighs one million milligrams.
      a) True       b) False

5. The laboratory practice of drying a known volume of water to evaporate off the water so that weight of the remaining residue can be determined, may miss the following portion of total dissolved solids.
      a) Silica
      b) Sulfate
      c) Sodium
      d) Carbon dioxide

6. The capacity of cation and anion resins to take up and hold respective ions depends on the weight and valence of each specific ion.
      a) True       b) False

7. Equivalent weight is used as the means of making individual ions equivalent in the amount of capacity they will take up in an ion exchange resin bed.
      a) True       b) False

8. Equivalent weight is determined by _______.
      a) dividing an ion's electric charge (valence) by its atomic or molecular weight
      b) dividing the weight of the ion by its valence
      c) multiplying the concentration of the ion by 50 (the equivalent weight of calcium carbonate)
      d) dividing parts per million of the respective ion concentration by 17.1

9. Equivalents per million (epm) of ionic substances in water is the same as _______.
      a) milliequivalents per liter (meq/L)
      b) ppm as ion divided by the ion's equivalent weight
      c) mg/L as ion divided by the ion's equivalent weight
      d) b and c
      e) all of the above

10. The water analysis expression most commonly used in calculations to determine the capacity of ion exchange resin systems in English units is _______.
      a) ppm or mg/L as calcium carbonate (CaCO3)
      b) total dissolved solids
      c) total hardness
      d) nephelometric turbidity units (NTU)