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

Hyponatremia Ions play a critical role in maintaining biological function. E.g. Na +, Ca 2+, 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.

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.

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” water.htmlwww.mashinc.org/resources-essay- water.html

Prevention of Water Intoxication Drink sodium containing sports drinks /v08n1/gatorade.htmlhttp:// /v08n1/gatorade.html Eat salty foods Avoid aspirin, ibuprofen

pH Balance in the Body Blood pH = [ 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, CO 2 ) that must be excreted Two mechanisms are –Respiration –Metabolism

Respiration Lungs exhale CO 2 ; CO 2 + H 2 O  H 2 CO 3 –Respiratory acidosis occurs if breathing is impaired –Respiratory alkalosis occurs if too much CO 3 is exhaled. Hyperventilation, high altitudes

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

Healthy Teeth Ca 5 (PO 4 ) 3 OH is hydroxyapatite and is a major component of teeth Ca 10 (PO 4 ) 6 (OH) 2 (s) ↔ 10Ca PO OH - 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

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

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.

List of Antacids AntacidReactionHealth Effects Al(OH) 3 + 3HCl  AlCl 3 + 3H 2 O Interferes with antibiotic absor; constipation TUMS ® CaCO 3 + 2HCl  CaCl 2 + 2H 2 O hypercalcemia Milk of Magnesia Mg(OH) 3 + 2HCl  MgCl 2 + 2H 2 O Long lasting, fast acting; laxative Alka- Seltzer NaHCO 3 + HCl  NaCl + H 2 CO 3 Fast acting but short lasting, fluid retention

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)

Why Soil pH Decreases Leaching of basic ions (group IA, IIA ions) Increase in CO 2 [CO 2 + H 2 O  H 2 CO 3 Decay of organic matter  acids Oxidation of N- and S- containing fertilizers –N + oxygen  NO 2  HNO 3 –S + oxygen  SO 3  H 2 SO 4

How to Increase Soil pH Add lime –CaO + H 2 O  Ca(OH) 2 – calcic limestoneCaCO 3  CaO + CO 2 –Dolomite limestone CaMg(CO 3 ) 2  CaO, MgO Added benefit is the increase in essential calcium and magnesium ions Lime also increases availability of nitrogen and absorption of phosphorus ph/htm