1. Hard Water

2. Clogged Pipes – Hard Water limestone hard water carbonic acid Step 1: Acid rain is formed Step 2: Acid rain dissolves limestone Water softener H 2 O + CO 2 H 2 CO 3 H 2 CO 3 + CaCO 3 Ca(HCO 3 ) 2 H 2 CO 3 + MgCO 3 Mg(HCO 3 ) 2

3. Pipes develop Scales Step 3: Hard water is heated and deposits scales Ca(HCO 3 ) 2 CaCO 3 (s) + H 2 O + CO 2 Mg(HCO 3 ) 2 MgCO 3 (s) + H 2 O + CO 2 scales on pipes 1 gram = 1 / 7000th pound 300 gallons / day with 10 grain water supply

4. No More Hard Water Scale No More Ugly Hard Water Spotting Protects Plumbing and Appliances Saves Money on Cleaning Products

5. Water Purification Hard Water Cation Exchanger Anion Exchanger Deionized Water (a) (b)(c) H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ OH - (a)The cations in hard water are exchanged for H +. (b)The anions in hard water are exchanged for OH -. (c)The H + and OH - combine to give H 2 O. Hard water is softened by exchanging Na + for Ca 2+, Mg 2+, and Fe 3+. Corwin, Introductory Chemistry 2005, page 361 Na + Ca 2+ Mg 2+ Fe 3+

6. Which ions are removed from hard water to produce soft water? Hard water is softened by exchanging Na + for Ca 2+, Mg 2+, and Fe 3+. Na + (aq) + H (resin) Na (resin) + H + (aq) Cl - (aq) + (resin) OH (resin) Cl + OH - (aq) Notice that the ion exchange resin produces both hydrogen ions and hydroxide ions which can readily combine to give water. H + (aq) + OH - (aq) H 2 O (aq) The net result is that the resin removes all ions from water passing through the deionizing system. Corwin, Introductory Chemistry 2005, page 361

7. Calcium (Ca 2+ ) and Magnesium (Mg 2+ ) Ions in Untreated Water Sodium (Na 1+ ) Ions on beads Calcium (Ca 2+ ) and Magnesium (Mg 2+ ) Ions on beads Sodium (Na 1+ ) Ions in Treated Water