APPLICATIONS OF CHAPTER 11

1. APPLICATIONS OF CHAPTER 11 Hyponatremia, Gatorade pH Balance in Body Healthy Teeth Antacids pH and Soil

2. Hyponatremia • Ions play a critical role in maintaining biological function. E.g. Na+, Ca2+, K+ • These ions are important in the nervous system, brain function, regulation, etc • If a person drinks excess water, the water goes to the digestive system and then to the blood.

3. Hyponatremia (2) • This results in a sharp drop in the concentration of ions (molarity) in the blood. • In the brain, the result is an inequality between [ions in blood] << [ions in brain]. • This causes excess water to be transported into the brain to reduce [ions in brain] and cause a concentration balance.

4. Hyponatremia (3) • The excess water causes the swelling of brain cells, diarrhea, over-salivation, stupor, vomiting, muscle tremors; death can result. • Water intoxication • “Water of Life, Water of Death” • www.mashinc.org/resources-essay-water.html

5. Prevention of Water Intoxication • Drink sodium containing sports drinks • http://www.rgp.ufl.edu/publications/explore/v08n1/gatorade.html • Eat salty foods • Avoid aspirin, ibuprofen

6. pH Balance in the Body • Blood pH = [7.0-7.8 with 7.4 normal level] • Small deviations from this pH range can lead to disease and possible death • The human body makes a lot of acid (gastric juices, CO2) that must be excreted • Two mechanisms are • Respiration • Metabolism

7. Respiration • Lungs exhale CO2; CO2 + H2O  H2CO3 • Respiratory acidosis occurs if breathing is impaired • Respiratory alkalosis occurs if too much CO3 is exhaled. Hyperventilation, high altitudes

8. Metabolism • Metabolism and the blood’s ability to carry acid away determines body pH. • Metabolic acidosis occurs in severe diabetes, kidney failure and severe diarrhea • Metabolic alkalosis occurs in severe vomiting, excess diuretic use • http://www.e-kidneys.net/acidbase.html

9. Healthy Teeth • Ca5(PO4)3OH is hydroxyapatite and is a major component of teeth • Ca10(PO4)6(OH)2 (s) ↔ 10Ca2+ + 6PO43- + 2OH- • This is an equilibrium rxn between solid tooth material and dissolved ions. • Changes in pH can cause more tooth to form or teeth to dissolve • http://www.oralchelation.com/calcium/p7.htm

10. Antacids • See Handout • Antacids are weak bases and they neutralize stomach acid or gastric juices. • Each antacid can be characterized by a chemical reaction, antacid efficiency, and side effects • http://www.e-antacid.com

11. Antacids • Antacids are weak bases that neutralize the acid (HCl, gastric juices) in the gastrointestinal system. • Antacids differ in solubility, neutralizing capacity, time of reaction, time of effectiveness, price, side effects.

12. List of Antacids

13. Soil pH • Plants obtain most essential nutrients from the soil in the form of dissolved ions. • Soil pH determines the solubility of these ions and therefore, the health of plants. • Soil pH should be slightly acidic (pH = 6-7)

14. Why Soil pH Decreases • Leaching of basic ions (group IA, IIA ions) • Increase in CO2 [CO2 + H2O  H2CO3 • Decay of organic matter  acids • Oxidation of N- and S- containing fertilizers • N + oxygen  NO2  HNO3 • S + oxygen  SO3  H2SO4

15. How to Increase Soil pH • Add lime • CaO + H2O  Ca(OH)2 • calcic limestone CaCO3 CaO + CO2 • Dolomite limestone CaMg(CO3)2 CaO, MgO • Added benefit is the increase in essential calcium and magnesium ions • Lime also increases availability of nitrogen and absorption of phosphorus • http://www.esf.edu/pubprog/brochure/soilph/soilph/htm