! ! ! ! ! ! ! ! ! Tvcnjuufe!cz!!

Tvcnjuufe!cz!!
Name : .............................................
Class : ....................
 CERTIFICATE

This is to certify that .....................................................................,

Reg. No. ............................ of class XII of GREEN PARK

INTERNATIONAL SENIOR SECONDARY SCHOOL has

successfully completed his / her project report in chemistry on the topic

“ Comparitive study of commercial antacids....” for the

partial fulfillment of AISSCE as prescribed by the CBSE in the year

2018 - 2019.

Viva voce held on :

Registration No :

Signature of the Guide Signature of the principal

Signature of the Internal Signature of the External

Examiner Examiner
 ACKNOWLEDGEMENT

At the outset, I express our gratitude to the Almighty Lord

for the divine guidance and wisdom showered on me to

undertake this project.

I am immensely grateful to my beloved Principal for her

involvement in this project by providing useful inputs and timely

suggestions.

I am also thankful to my Chemistry teacher for her

guidance and help to make this project a success.

My Parents also played a key role in shaping up this project

nicely and I convey my special thanks to them as well.

CONTENT

Š Bjn!pg!uif!qspkfdu!!
Bjn!pg!uif!qspkfdu!!

Š Jouspevdujpo!
Jouspevdujpo!

Š Uifpsz!
Uifpsz!

Š Sfrvjsfnfout!
Sfrvjsfnfout!

Š Qspdfevsf!
Qspdfevsf!

Š Pctfswbujpot!
Pctfswbujpot!

Š Sftvmu!
Sftvmu!

Š Cjcmjphsbiqz

!
Aim :
L To analyze the given samples of commercial antacids by determining the
amount of hydrochloric acid they can neutralize.

Introduction :
L It is well known that the food we take undergoes a series of complex
reactions within the body which constitute digestion and metabolism. These

reactions are catalyzed by enzymes which are very specific in their action

and can function properly only when the pH of the medium is within a

specific range.

L Some enzymes require mildly alkaline conditions while others operate only in
weakly acidic media. The enzymes control the digestion of proteins present

in the food as it reaches the stomach. In the stomach, dilute hydrochloric

acid is secreted and it provides mildly acidic conditions required for the

functioning of protein digesting enzymes in the stomach.

L Gastric acid is a digestive fluid, formed in the stomach. It has a pH of 1.5 to

3.5 and is composed of 0.5 % hydrochloric acid (HCl). It is produced by cells

lining the stomach, which are coupled to systems to increase acid production

when needed.

L Other cells in the stomach produce bicarbonate to buffer the acid, ensuring
the pH does not drop too low (acid reduces pH). Also cells in the beginning of

the small intestine, or duodenum, produce large amounts of bicarbonate to

completely neutralize any gastric acid that passes further down into the

digestive tract. The bicarbonate-secreting cells in the stomach also produce

and secrete mucus. Mucus forms a viscous physical barrier to prevent gastric

acid from damaging the stomach.

L However, sometimes the stomach begins to secrete an excess of HCl. This
leads to a condition known as Gastric Hyperacidity. This condition can also
be triggered by the intake of to much food or highly spiced food. This, in
turn, makes the stomach lining cells to secrete more acid resulting in
Hyperacidity. It also leads to acute discomfort due to indigestion.

L To counter this situation, substances like Antacids or literally anti - acids,

have been developed. Antacids are commercial products that neutralize the
excess acid in the stomach providing a sensation of relief to the person. The
action of antacids is based on the fact that a base can neutralize an acid
forming salt and water.

L Common antacids satisfy the condition – right amount of alkali that can
neutralize the acid. If the content of alkali in the antacid is too high, no
doubt acidity is relieved, but it’ll create alkaline conditions that makes the
digestive enzymes ineffective.

L To make sure that the pH of the stomach remains in a specific range, many
substances are added to the antacids.
Theory :
L Antacids react with excess stomach acid by neutralization.
HCl + NaOH → H2O + NaCl

L During the process, hydrogen ions H+ from the acid (proton donor) or a
hydronium ion H3O+ and hydroxide ions OH- from the base (proton acceptor)
react together to form a water molecule H2O.
L In the process, a salt is also formed when the anion from acid and the cation
from base react together. Neutralization reactions are generally classified as
exothermic since heat is released into the surroundings.
L Acids are proton donors which convert into conjugated bases. They are
generally pure substances which contain hydrogen ions (H+) or cause them
to be produced in solutions.
L Hydrochloric acid (HCl) and sulfuric acid (H2SO4) are common examples. In
water, these break apart into ions:

HCl → H+(aq) + Cl- (aq)

(OR)
H2SO4 → H+(aq) + HSO4-(aq)

L Bases are proton acceptors which convert into conjugated acids. They are
generally substances which contain hydroxide ion (OH-) or produce it in
solution.
L Alkalis are the soluble bases, i.e. a base which contains a metal from group 1
or 2 of the periodic table. To produce hydroxide ions in water, the alkali
breaks apart into ions as below:

NaOH→Na+(aq)
NaOH→ -
(aq)+OH (aq)

L Examples of bases include sodium hydroxide (NaOH), potassium hydroxide

(KOH), magnesium hydroxide (Mg(OH)2), and calcium hydroxide (Ca(OH)2).
Antacids are generally bases.
Requirements :
a.Apparatus:

L Burette(50ml)

L Pipette(20ml)

L Conical Flasks(250ml)

L Measuring Cylinder(10ml)

L Beakers(100ml)

L Standard Flasks(100ml)

L Filter Paper

L Funnel

L Bunsen Burner

L Weighing machine

L Clean & glazedwhite tile

L Glass Rod

L Water

L Crusher
b. Chemicals:

L NaOH powder

L Na2CO3 powder

L 10M conc. HCl acid

L Four different brands of antacids

L Phenolphthalein

L Methyl Orange
Procedure :

L First prepare 1 litre of approximately N/10 solution of HCl by diluting 10ml of

the given 10M HCl acid to 1litre.

L Next prepare1litre of approx.N/10NaOH solution by dissolving 4.0g of NaOH

to make1litre of solution.

L Similarly prepare N/10 Na2CO3 solution by weighing exactly 1.325g of

anhydrous Na2CO3 and then dissolving it in water to prepare exactly 0.25L or

250 ml of Na2CO3 solution.

L Now, standardize the HCl solution by titrating it against the standard

Na2CO3 solution using methyl orange as indicator.

L Similarly standardize the NaOH solution by titrating it against standardized

HCl solution using phenolophtahlein as indicator. Stop the titration when the

pink colour of the solution disappears.

L Now, powder the four antacid samples and weigh 0.5 g of each.
L Add 25 ml of the standardised HCl to each of the weighed samples taken in
conical flasks. Make sure that the acid is in slight excess so that it neutralize

all the basic character of the tablet powder.

L Add a few drops of phenolphthalein indicator and warm the flask over a
bunsen burner till most of the powder dissolves.

L Filter the insoluble material.

L Titrate this solution against the standardized NaOH solution till a permanent
pinkish tinge is obtained.

L Repeat the same experiment for all other samples too.

Observations :
L Standardisation of HCl solution:

Volume of 0.1N Na2CO3 taken is 20 ml

Indicator used is Methyl Orange

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1. 0 17 17
2. 18 35 17

Applying normality equation,

N 1 V1 = N 2 V2
(acid) (base)

N1 x 17 = 0.1 x 20
Normality of HCl, N1= 2/17 = 0.11 ≈ 0.1

Standardization of NaOH Solution:

L Volume of the given NaOH solution taken is 20.0 ml

Indicator used is Phenolphthalein
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Cvsfuuf!sfbejoht! Wpmvnf!pg!!
Op/!
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1. 0 16 16
2. 17 33 16

Volume of acid used = 16 ml

Applying normality equation,
N1 V’1 = N’2 V’2
(acid) (base)
0.11 x 16 = N’2 x 20
Normality of HCl, N’2 = (0.11*16) / 20 = 0.09 ≈ 0.1
L Analysis of antacid tablets:
• Weight of the antacid tablet powder = 0.5 g

• Volume of HCl solution added = 30 ml

• Volume of sample solution taken for titration = 20 ml

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1. Eno pineapple 29
2. Eno Lemon 24
3. Digene Lime 9
4. Omez 24
5. Pephyrous 40
6. Gelusil 22

Result :
L 1g of Eno Pineapple required 29 ml of Sodium Hydroxide (NaOH) to titrate it
completely.
L 1 g of Eno Lemon required 24 ml of Sodium Hydroxide (NaOH) solution to
titrate it completely.
L 1 g of Digene lime required 9 ml of Sodium Hydroxide (NaOH) to titrate it.
L 1 g of Omez required 24 ml of Sodium Hydroxide (NaOH) to titrate it
completely.
L 1 g of Pephyrous required 40 ml of Sodium Hydroxide (NaOH) to titrate it
completely.
L 1 g of Gelusil required 22 ml of Sodium Hydroxide (NaOH) to titrate it
completely.
L Based on the hypothesis of the experiment, the antacid which requires the
least amount of Sodium Hydroxide (NaOH) is the best antacid. From the
recorded observation, Digene© requires the least (5 ml), and is therefore the
best Antacid.
 bibliography
L http://www.reachoutmichigan.org/funexperiments/quick/csustan/ antacid

L http://ien2.uneche.maine.edu/genchemlabs/Antacid /antacid2.htm

L http://www.chem.latech.edu/~deddy/chem104/104 Antacid.htm

L http://www.images.google.com

L http://www.wikipedia.com
Introduction

The human digestive system is a complex network of organs and processes designed to break

down food into absorbable nutrients.

A critical component of this system is the secretion of hydrochloric acid (HCl) in the stomach, which

helps maintain an acidic environment crucial for enzymatic digestion, particularly of proteins.

The stomach's acid also acts as a defense mechanism against pathogens. However, the production

of gastric acid must be finely regulated, as excessive secretion can lead to conditions like acid reflux

or gastritis.

Antacids were developed as therapeutic agents to combat the discomfort caused by excess

stomach acid. They work by neutralizing excess HCl, thereby providing relief from symptoms such

as heartburn and indigestion.

Modern commercial antacids come in various forms, including tablets, syrups, and powders, and

utilize different active ingredients like calcium carbonate, magnesium hydroxide, and aluminum

hydroxide.

This comparative study will also delve into the chemical principles underlying antacid function,

emphasizing neutralization reactions and their role in alleviating acidity.

Understanding these principles will provide deeper insights into the mechanisms that make certain

antacids more effective than others.

Observations

Standardization of Solutions:

1. Hydrochloric Acid (HCl): Standardized using sodium carbonate (Na2CO3) as a primary standard.

The reaction between HCl and Na2CO3 is a classic acid-base reaction, producing CO2 and water.

2. Sodium Hydroxide (NaOH): Standardized against the previously standardized HCl solution using

phenolphthalein as an indicator. The endpoint was observed as the disappearance of the pink color.

Analysis of Antacid Tablets:

- Each tablet was crushed into fine powder to ensure uniformity during the reaction with HCl.

- 25 mL of standardized HCl solution was added to 0.5 g of the antacid powder, ensuring slight

excess to neutralize all active alkaline components.

- Residual acid was titrated with standardized NaOH using phenolphthalein as an indicator, and the

volume of NaOH required was recorded.

- Observations indicated significant variations in neutralizing capacity among the different brands,

highlighting differences in composition and effectiveness.

Key Trends Noted:

- The volume of NaOH required for neutralization varied between brands, correlating with the active

ingredients and their concentrations.

- Some brands exhibited rapid neutralization, suggesting a higher content of strong bases like

calcium carbonate.
Results

Quantitative Analysis of Neutralizing Capacity:

- The volume of NaOH used to titrate the residual HCl provided a direct measure of each antacid's

neutralizing ability. For instance:

- Eno Pineapple: 29 mL of NaOH required per gram of antacid.

- Digene Lime: 9 mL of NaOH required per gram of antacid.

Effectiveness Ranking:

- Based on the hypothesis that lower NaOH usage indicates higher effectiveness, Digene emerged

as the most efficient antacid in this study.

- Pephyrous required the highest volume of NaOH (40 mL), suggesting it is less effective compared

to other brands.

Insights into Active Ingredients:

- Brands with calcium carbonate as the primary ingredient demonstrated high neutralizing capacity,

reflecting its strong basic properties.

- Antacids containing magnesium hydroxide or aluminum hydroxide showed moderate efficacy,

potentially due to their slower reaction rates with HCl.

Economic Considerations:

- While effectiveness is a critical parameter, cost per gram of active ingredient also influenced

consumer preferences. This study found a significant variation in cost-efficiency among the brands.