Transcript Antacids - Dr. More Chemistry

Antacids
Acid Base Chemistry
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Antacids
12.2 Antacids
• State and Explain how excess acidity
in the stomach can be reduced by the
use of different bases.
• Antacids: bases, metal oxides,
hydroxides, carbonates, hydrogen
carbonates
• Reacts with stomach acid (excess) to
adjust the stomach pH to the desired
level
Purpose of HCl in the stomach
• To suppress growth of harmful
bacteria
• To help in digestion by hydrolyzing
proteins to amino acids
• Normal pH of stomach acid ~
• 1.2 – 0.3 range,
• Stress also produces more acid
Role of antacids
• Neutralizes the excess acids and
relives the discomfort
–Excess acid can cause ulcers
Examples: Over the Counter
• Al(OH)3 Mg(OH)2 CaCO3
• NaHCO3
Alginates
• Antacids are combined with
Alginates
• extracted from brown sea weeds
• produces neutralizing layer that
prevents acid reflux / acid
entering into oesophagus
Dimethicone / Antifoaming agent
• Are added to antacids to reduce the surface
tension of gas bubbles
• And produce de-foaming action
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• The possibilities offered to the
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Active ingredients of some
commercial antacids
• Tums: CaCO3 MgCO3 Mg Si3O8
–For the treatment of gastritis
and of ulcers
• Rolaids : AlNa(OH)2CO3
• Malox : Al(OH)3 Mg(OH)2
• Alka Seltzer : NaHCO3 , citric acid,
aspirin
Alka Seltzer : NaHCO3 , citric acid,
aspirin
Active ingredients of some
commercial antacids
• Milk of Magnesia : Mg(OH)2 or
MgO/Mg(OH)2
mixture
• Amphogel Al(OH)3
• Di-Gel : CaCO3
Action of Antacids
• Mg2Si3O8
•
+ 4 HCl
3 SiO2(s)
2 H2O (l) + 2 MgCl2(aq)
• Write the reactions for rest of the antacids
• Alkalosis: high doses of antacids
• basic stomach
• Other problems: body produces
more acids