Antacids, Organic and Non
Organic Components
A study into the effectiveness in different organic and non
organic compounds in antacids
Tums
Per Tablet:
-
1000 mg CaCO3 (inorganic antacid)
-
410 mg Elemental Ca
-
5 mg Mg
-
2 mg Na
Milk of Magnesia
Per 20 mL:
-
1600 mg Mg(OH)2 (saline laxative & antacid)
Gaviscon
Per 20 mL:
-
1000 mg Sodium Alginate (organic)
-
426 mg NaHCO3 (inorganic antacid)
-
650 mg CaCO3 (inorganic antacid)
Alka Seltzer
Per Tablet:
-
325 mg Aspirin (painkiller - acetylsalicylic acid)
-
1916 mg NaHCO3 (inorganic antacid)
-
1000 mg Citric Acid (makes it fizzy)
Purpose
-
Determine purpose and function of
organic and inorganic components
-
Determine which components had the
most effectiveness or unique functions
Inorganic agents
-
CaCO3
-
Mg(OH)2
-
NaHCO3
-
All are Bases, Main active agents
Organic agents
-
Citric Acid
-
Sodium Alginate
-
Aspirin
-
Provide more specific functions
Analysis
-
Organic component functions
-
Side effects
-
Alkalosis (blood pH above 7.45 - may be caused by antacids absorbed into bloodstream)
Experiments
-
Titration
-
Buffer Zone
-
Rate of Rxn
-
Enthalpy
Organic Components
Citric Acid
Effervescence (fizzy) agent in Alka Seltzer
C6H8O7(aq) + 3NaHCO3(aq) → Na3C6H5O7(aq) (sodium citrate) + 3CO2(g) + 3H2O(l)
Sodium citrate makes it taste better (found in ice cream, jam, etc.)
Also acts as a buffering agent (maintains pH)
Aspirin
Used in Alka Seltzer
Pain relief
Anti Inflammatory effects
Main cause of Alka Seltzer’s side effects
Alginate
Sodium alginate is used in Gaviscon
NaC6H7O6 + HCl → C6H8O6 + NaCl
H+ and Na+ ions undergo ion exchange
Ca2+ forms a ionic bond with the Carboxylate (COO- groups) in Alginic acid
The resulting is sort of a crystal lattice with gel like properties
Gel forms a barrier preventing acid reflux
Gel has high water retention due to Alginates natural properties
Inorganic Components
CaCO3
CaCO3 + 2HCl → CaCl2 + CO2 + H2O
CaCl2 is soluble salt
CO2 can cause feelings of bloatedness or uncomfort
Mg(OH)2
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
MgCl2 is soluble salt
Titration / Buffer
Setup
Tums: Crushed 1 tablet in mortar and pestle, put into 100 mL water, titrated
Alka Seltzer: Droppen 1 tablet into 100 mL water, titrated
Gaviscon: 5 mL measured, diluted with 100 mL water, titrated
Milk of magnesia: 5 mL measured, diluted with 100 mL water , titrated
All antacids titrated with 0.1 M HCl
Tums Titration
Gaviscon Titration
Alka Seltzer Titration
Phillips Titration
Antacid
mL HCl (0.1M) titrated
Approx. length of buffer zone
Tums
250 ml
110 ml (low pH)
Gaviscon
45 ml
30 ml (slight)
Alka Seltzer
255 ml
Non-existent or Everything
Milk of Magnesia
167 ml
100 ml (high pH)
= strong antacid
= long lasting (takes longer
to work)
= weak antacid
= short lasting (works faster)
Rates / Enthalpy
Setup
Tums: Crushed 1 tablet in mortar and pestle, put into acid (100mL 0.1M)
Alka Seltzer: Droppen 1 tablet into acid (100mL 0.1M)
Gaviscon: 5 mL measured, poured into acid (100 mL 0.1M)
Milk of magnesia: 5 mL measured, diluted with 15 mL water, poured into acid (100
mL 0.1M)
Tums Rates/Enthalpy
Gaviscon Rates/Enthalpy
Phillips Rates/Titration
Alka Seltzer Rates/Titration
Antacid
Delta Time
Enthalpy
Rate of Rxn
Tums
17.5 s
3.6 °C
0.21 °C/s
Gaviscon
25 s
2.8 °C
0.11 °C/s
Phillips
17.5 s
4.0 °C
0.23 °C/s
Alka
12.5 s
4.0 °C
0.32 °C/s
= stomach
discomfort
= comfort
Side Effects
Tums
Constipation (due to calcium)
Hypercalcemia (due to calcium)
Acid Hypersecretion (due to body natural response)
Milk of Magnesia
Diarrhea (magnesium hydroxide is a laxative)
Hypermagnesemia: (leads to heart problems, hypotension if kidneys cannot filter it
out)
Gaviscon
Balances constipating effects with a laxative effect