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Anallysis of antacids to find out which is the best commercial antacid

Indigestion? which is the best commercial antacid?

Objectives

  • Measure the quantity of commercial antacid required to neutralize a simulated stomach acid (0.15 M hydrochloric acid) and then compare the effectiveness of several brands of antacids in neutralizing acids.
  • Learn and practice the back-titration method.

Grading

You grade will be determined according to the following:

  • Pre-lab (10%)
  • Lab Report Form (80%)
  • TA points (10%)

Introduction

The parietal cells in the stomach secrete hydrochloric acid at a quite high concentration of about 0.155 M. The flow of HCl increases when food enters the stomach. When you eat or drink too much, your digestive system may generate too much acid. You may develop a condition called "heartburn" or indigestion. Antacids are swallowed to neutralize this excess acid and "relieve" but not eliminate the condition. The reaction that takes place is an acid/base reaction. A small amount of NaOH might be as effective, although rough on the rest of the digestive system, so antacids have been formulated to reduce acidity while avoiding physiological side-effects. Many antacids use CaCO 3 size 12{ ital "CaCO" rSub { size 8{3} } } {} for this purpose.

In addition to the active ingredient (base), tablets may also contain flavors, sweeteners, binders, fillers, antifoam agents, pain relievers (aspirin), etc. In this experiment, the tablets will be analyzed only for their ability to neutralize acids. The base in antacids varies with the brand. Below is an example of active agents in several brands.

  Brand Active Agent Base
Pepto-Bismol BiO ( HOC 6 H 4 COO ) size 12{ ital "BiO" \( ital "HOC" rSub { size 8{6} } H rSub { size 8{4} } ital "COO" \) } {}
Milk of Magnesia Mg ( OH ) 2 size 12{ ital "Mg" \( ital "OH" \) rSub { size 8{2} } } {}
Rolaids NaAl ( OH ) 2 CO 3 size 12{ ital "NaAl" \( ital "OH" \) rSub { size 8{2} } ital "CO" rSub { size 8{3} } } {} (newer tablets: CaCO 3 size 12{ ital "CaCO" rSub { size 8{3} } } {} )
Tums CaCO 3 size 12{ ital "CaCO" rSub { size 8{3} } } {}
Alka-Seltzer II NaHCO 3 size 12{ ital "NaHCO" rSub { size 8{3} } } {} and KHCO 3 size 12{ ital "KHCO" rSub { size 8{3} } } {}
Maalox Mg ( OH ) 2 size 12{ ital "Mg" \( ital "OH" \) rSub { size 8{2} } } {} and Al ( OH ) 3 size 12{ ital "Al" \( ital "OH" \) rSub { size 8{3} } } {}
Gaviscon Al ( OH ) 3 size 12{ ital "Al" \( ital "OH" \) rSub { size 8{3} } } {}

 Acids are neutralized by these bases as illustrated below.

BiO ( HOC 6 H 4 COO ) + 3H + ( aq ) Bi 3 + ( aq ) + H 2 O ( l ) + HOC 6 H 4 COOH ( s ) size 12{ ital "BiO" \( ital "HOC" rSub { size 8{6} } H rSub { size 8{4} } ital "COO" \) +3H rSup { size 8{+{}} } \( ital "aq" \) rightarrow ital "Bi" rSup { size 8{3+{}} } \( ital "aq" \) +H rSub { size 8{2} } O \( l \) + ital "HOC" rSub { size 8{6} } H rSub { size 8{4} } ital "COOH" \( s \) } {}
Mg ( OH ) 2 ( s ) + 2H + ( aq ) Mg 2 + ( aq ) + 2H 2 O ( l ) size 12{ ital "Mg" \( ital "OH" \) rSub { size 8{2} } \( s \) +2H rSup { size 8{+{}} } \( ital "aq" \) rightarrow ital "Mg" rSup { size 8{2+{}} } \( ital "aq" \) +2H rSub { size 8{2} } O \( l \) } {}
Al ( OH ) 3 ( s ) + H + ( aq ) Al ( OH ) 2 + ( aq ) + H 2 O ( l ) size 12{ ital "Al" \( ital "OH" \) rSub { size 8{3} } \( s \) +H rSup { size 8{+{}} } \( ital "aq" \) rightarrow ital "Al" \( ital "OH" \) rSub { size 8{2} } rSup { size 8{+{}} } \( ital "aq" \) +H rSub { size 8{2} } O \( l \) } {}
Al ( OH ) 2 + ( aq ) + H + ( aq ) Al ( OH ) 2 + ( aq ) + H 2 O ( l ) size 12{ ital "Al" \( ital "OH" \) rSub { size 8{2} } rSup { size 8{+{}} } \( ital "aq" \) +H rSup { size 8{+{}} } \( ital "aq" \) rightarrow ital "Al" \( ital "OH" \) rSub { size 8{2} } rSup { size 8{+{}} } \( ital "aq" \) +H rSub { size 8{2} } O \( l \) } {}
CaCO 3 ( s ) + H + ( aq ) Ca 2 + ( aq ) + HCO 3 ( aq ) size 12{ ital "CaCO" rSub { size 8{3} } \( s \) +H rSup { size 8{+{}} } \( ital "aq" \) rightarrow ital "Ca" rSup { size 8{2+{}} } \( ital "aq" \) + ital "HCO" rSub { size 8{3} } rSup { size 8{ - {}} } \( ital "aq" \) } {}
HCO 3 ( aq ) + H + ( aq ) CO 2 ( g ) + H 2 O ( l ) size 12{ ital "HCO" rSub { size 8{3} } rSup { size 8{ - {}} } \( ital "aq" \) +H rSup { size 8{+{}} } \( ital "aq" \) rightarrow ital "CO" rSub { size 8{2} } \( g \) +H rSub { size 8{2} } O \( l \) } {}

In this simple experiment you will find the neutralizing capacity of various commercial antacid tablets. To test their capacity to neutralize acid, we will first dissolve an appropriate and measured amount of the sample in a simulated stomach environment. This is a solution containing a known quantity of HCl that will react with all of the antacid and still leave some extra HCl. Then we will determine how much of the original HCl remains by titrating it to neutrality with a standardized solution of NaOH. Simple subtraction will reveal how much of the acid was neutralized by the antacid tablet. This general method of analysis is called back-titration.

Note: The standardized solutions of NaOH and HCl have been prepared for you. However you need to understand how and why it is done this way. (See Supporting Information on this) Also see notes on Titration Tips.

If N A size 12{N rSub { size 8{A} } } {} is the total number of moles of HCl, and N B size 12{N rSub { size 8{B} } } {} is the number of moles of NaOH needed to back-titrate the excess HCl, then, N sample is the number of moles neutralized by the sample:

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
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Bhagvanji
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Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
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Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
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Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
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Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
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Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
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Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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Source:  OpenStax, General chemistry lab spring. OpenStax CNX. Apr 03, 2009 Download for free at http://cnx.org/content/col10506/1.56
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