1. Antacids Assessment Statement
- State and explain how excess acidity in the stomach can be reduced by the use of different bases.

2. Stomach Acidity Stomach cells secrete
hydrochloric acid (HCl)  providing an acidic
environment (pH of 1-2)
Benefits of acidic environment:
kill bacteria
provide optimum pH for digestive enzymes (ex. Pepsin)

3. - IB Questions A: hydrochloric acid
Q: Identify the substance responsible for low pH of the liquid in the stomach
A: hydrochloric acid

4. Stomach Acidity Excess Stomach Acidity
Cause: alcohol, smoking, stress, anti inflammatory drugs
Outcomes:
acid indigestion – discomfort feeling from too much acid
heartburn – acid rising into the esophagus (acid reflux)
ulcer – damage to the lining of the stomach wall, results in tissue loss and inflammation
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5. - IB Questions
Q: Explain how heartburn is caused A: Heartburn is caused by the acid rising up to the esophagus

6. What is Antacids? drugs that work to neutralize HCl in the stomach
relieve discomforts
adjust the pH of the stomach to the desire level of acidity

7. Compounds of Antacids all compounds of antacids are WEAK BASIC
Compounds/Ingredients:
- metal oxides
- metal hydroxides { Al(OH)3 , Mg(OH)2 }
- carbonates { CaCO3 }
- hydrocarbonates { NaHCO3 }

8. Compounds of Antacids
metal oxides/ hydroxides + HCl  salt + H2O carbonates/ hydrocarbonates +HCl  salt + H2O + CO2

9. Neutralization of HCl
Examples: 1. magnesium oxide 2. magnesium hydroxide 3. aluminum hydroxide 4. calcium carbonate 5. sodium hydrocarbonate
Remember to balance the equations!!!

10. Neutralization of HCl MgO + 2HCl  MgCl2 + H2O
Mg(OH)2 + 2HCl  MgCl2 + 2H2O
Al(OH)3 + 3HCl  AlCl3 + 3H2O
CaCO3 + 2HCl  CaCl2 + H2O + CO2
NaHCO3 + HCl  NaCl + H2O + CO2

11. - IB Questions A: aluminum, calcium, magnesium, sodium
Q: What are the metals that used in antacids?
A: aluminum, calcium, magnesium, sodium

12. Neutralization of HCl *** Notice the mole ratio of the reactions
the mole ratio determines the effectiveness when comparing compounds
Neutralization of HCl with aluminum hydroxide is the most effective
- Al can neutralize 3 moles of H+
ions / it has three OH- ions

13. Antacid Formulations
Can contains both magnesium and aluminum compounds Why both? - they act as complements of each others
Magnesium salts
Aluminum salts
Act faster
Dissolve slower, but long lasting relief
Relieve constipation
Cause constipation

14. Antacid Formulations With metal carbonates and hydrocarbonates .....
.... the production of CO2 gas may cause bloating and flatulence
CaCO3 + 2HCl  CaCl2 + H2O + CO2
NaHCO3 + HCl  NaCl + H2O + CO2

15. Antacid Formulations Solutions: (ex. dimethicone)
1) antifoaming agents are added to relieve the side effects
(ex. dimethicone)
2) ALGINATES are added to prevent reflux into the esophagus

16. Health Hazard!!! Antacids are not always necessary ….
High dose  a basic stomach – can cause discomforts, a condition called alkalosis
Antacids are not always necessary ….
…. frequent use can harmful to heart, kidney, or bones

17. - IB Questions
Q: Suggest why potassium hydroxide is not used as an antacid A: KOH is a strong base (alkali) so it would be dangerous for body cells; it is corrosive and would upset the pH

18. The End!