N A M E : - Z I N A B H AT TA C H A RY YA

CLASS :- XII
STREAM :- BIO SCIENCE
S U B J E C T : - C H E M I S T RY
BOARD ROLL NUMBER :-
SESSION :- 2024 - 2025

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TOPIC : - S T U D Y O F O X A L AT E I O N

C O N T E N T I N G U AVA F R U I T

DONE BY :- ZINA BHATTACHARYYA

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 INDEX

SL . NO . TOPIC PG . NO .
1. CERTIFICATE 4
2. ACKNOWLEDGEMENT 5
3. DECLARATION 6
4. ABSTRACT 7
5. INTRODUCTION (8-12)
6. AIM OF THE PROJECT 13
7. PROCEDURE (14-15)
8. CHEMICAL EQUATION 16
9. MATERIALS REQUIRED (17-20)
10. RESULT 21
11. CONCLUSION 22
12. BIBLIOGRAPHY 23

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 CERTIFICATE
This is to certify that [ZINA BHATTACHARYYA], a student of Class [XII], East Point School, has
successfully completed the chemistry project titled “[STUDY OF OXALATE ION CONTENT IN GUAVA
FRUIT]” under the guidance of [Arindam Ghosh].

The project has been completed as per the guidelines provided by the Chemistry Department of East Point
School. It demonstrates a good understanding of the subject and showcases [Zina Bhattacharyya]'s
dedication, thorough research, and hard work.

I am pleased to present this certificate in recognition of [Zina Bhattacharyya]'s efforts and

accomplishment.

Date:

Signature of Internal Examiner

Signature of External Examiner

Signature of Principal with stamp

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 ACKNOWLEDGEMENT
I would like to express my sincere gratitude to everyone who supported and guided me throughout
the completion of this chemistry project.

First and foremost, I extend my heartfelt thanks to our respected Principal, Sir [Principal's Name],
for providing us with excellent resources and a supportive environment at East Point School, which
made this project possible.

I am deeply grateful to my Chemistry Teacher, [Arindam Ghosh], for her/his invaluable guidance,
encouragement, and expertise. Her/his insightful feedback and continuous support motivated me to
explore the subject more deeply and enhanced my learning experience.

I would also like to thank my friends for their enthusiasm, cooperation, and teamwork throughout
the project. Their companionship made the entire process enjoyable and rewarding.

Finally, I am profoundly grateful to my family, whose constant support and encouragement helped
me stay focused and motivated.

Thank you all for your contributions and encouragement, without which this project would not have
been possible.

Signature of Student

(ZINA BHATTACHARYYA)
Date:
Place: 5
 DECLARATION

I, [Zina Bhattacharyya], a student of Class [XII] at East Point School, hereby declare that
the project titled “[STUDY OF OXALATE ION CONTENT IN GUAVA FRUIT]”
submitted for the chemistry course is my own work. This project has been completed
through my independent efforts and research under the guidance of [Arindam Ghosh].

I confirm that this project has not been copied from any other source, nor has it been
submitted previously for any other course or assessment. All sources and references used
have been duly acknowledged in the project.

I take full responsibility for the authenticity and originality of the work submitted.

Signature of Student

(ZINA BHATTACHARYYA)
Date:
Place:
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 ABSTRACT

TITLE :- OXALATE ION CONTENT IN GUAVA FRUIT : A COMPREHENSIVE STUDY

ABSTRACT :- The study investigates the presence of oxalate ions in

guava fruit at various ripening stages. Guava, a sweet and juicy fruit,
undergoes changes in its chemical composition during ripening. We
extracted oxalate ions from guava pulp samples using dilute sulfuric acid
and then titrated the resulting solutions against potassium permanganate.
Our observations and calculations revealed that the content of oxalate ions
increases as the guava fruit ripens. This finding has implications for dietary
considerations, as oxalate-rich foods can impact health, especially in
individuals with high urinary oxalate levels. Understanding the variation in
oxalate content during ripening helps us appreciate the nutritional aspects
of guava consumption.

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 INTRODUCTION

Guava, a popular tropical fruit, undergoes significant chemical changes as it ripens. One
intriguing aspect to study is the presence of oxalate ions in guava pulp. Oxalates are
compounds found in various foods and can form insoluble complexes with calcium in the
urine. Understanding their content in guava can have implications for dietary considerations.

In this experiment, we extract oxalate ions from guava samples using dilute sulphuric acid
and then titrate the resulting solutions against potassium permanganate. By comparing
fresh, semi-ripe, and ripe guava, we observe how the oxalate content varies during different
stages of ripening.

The results indicate that the content of oxalate ions increases as the guava fruit ripens.
This knowledge can help us appreciate the nutritional aspects of guava consumption and
its impact on health.

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Guava, a small, tropical fruit, has both delightful and alarming attributes. The
benefits of guava include its rich antioxidant properties, which help combat chronic
diseases like cancer and diabetes. Its extract has also been used in traditional
medicine to ease digestive issues and childbirth. Additionally, guava is an excellent
source of vitamins A and C, further supporting its role in maintaining overall health.
On the contrary, guava is known to cause allergic reactions in some individuals, and
its high levels of acidity can contribute to tooth erosion and digestive discomfort.
Moderation is key when consuming this tempting fruit.

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 WHAT IS OXALATE ?

Oxalate (systematic IUPAC name: ethanedioate) is an anion . This dianion is colorless. It

occurs naturally, including in some foods. It forms a variety of salts, for example sodium
oxalate (Na2C2O4), and several esters such as dimethyl oxalate ((CH3)2C2O4). It is a
conjugate base of oxalic acid. At neutral pH in aqueous solution, oxalic acid converts
completely to oxalate.
Oxalate ions, also known as oxalates, are
naturally occurring compounds found in
various foods and beverages. They are formed
when the body breaks down certain nutrients,
such as vitamin C, ascorbic acid, and certain
amino acids. While oxalate ions are generally
considered safe and essential for our bodies,
they can also have both positive and negative
effects. On the positive side, they play a crucial
role in maintaining healthy bones, skin, and
hair. However, excessive oxalate consumption
can lead to kidney stones, and high levels in the
body may be associated with certain health
conditions.

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Oxalates can be found in various foods and beverages. Some common sources of
oxalates include:

I. Leafy greens: Spinach, kale, Swiss chard, and beet greens are known for
their high oxalate content.

II. Vegetables: Rhubarb, beets, okra, and sweet potatoes are examples of
vegetables that contain oxalates.

III. Fruits: Certain fruits such as berries, figs, and kiwi are known to be high
in oxalates.

IV. Nuts and seeds: Almonds, peanuts, and sesame seeds are sources of
oxalates.

V. Cocoa and chocolate: Cocoa powder and products containing high

amounts of cocoa can also be significant sources of oxalates.

VI. Beverages: Some teas, especially black tea, as well as certain fruit juices,
can contain oxalates.

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It's important to note that while these foods contain oxalates, they also
provide important nutrients and health benefits. However, for individuals
who are at risk of kidney stones or have kidney-related conditions, it may
be advisable to moderate their intake of high-oxalate foods.

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 AIM OF THE PROJECT

To study the presence of oxalate ion content in guava fruit at different

stages of ripening .

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1) Crush the guava fruit to a fine pulp using a pestle and mortar . Then weigh 50 gm of
fresh guava pulp on the weighing machine .

2) Transfer the crushed pulp into a 500 ml beaker . Now , add about 50 ml of dil.H2SO4
solution to the beaker and boil the contents uniformly for about 2 minutes .

3) Cool and filter the contents into a 100 ml measuring flask . Then , add distilled water
to this flask until it reaches the 100 ml mark .

4) Take 10 ml of guava pulp solution into a titration / conical flask and add 5 ml of 1.0
M H2SO4 solution to it to prevent the formation of any precipitation of manganese
dioxide during the course of the titration .

5) Heat the solution up to 50 degree – 60 degree C before titrating it with potassium

permanganate solution taken in the burette . To increase the visibility of the colour
change , place the conical flask containing the solution to be titrated over a white
glazed tile kept below the nozzle of the vertically fitted burette .

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6) Rise and fill a clean burette with potassium permanganate solution . Remove the air
bubble , if any , from the nozzle of the burette by releasing some solution through it . The
burette used in the permanganate titration must have a glass stop cock as rubber is attacked
by permanganate ions .

7) Note the initial reading of the volume of permanganate solution in the burette and add it in
small volumes to the hot oxalic acid solution while swirling the contents of the flask gently .

8) The appearance of permanganate PALE PINK colouration in the titrand marks the
completion of the titration .

9) Repeat the titration till three concordant readings are obtained . Since the solution of
KMO4 is of dark colour , the upper meniscus should be considered for noting the burette
readings.

10) Repeat the above steps with 50 gm of –

• 1 – day old guava

• 3 – day old guava
• Week ( 7-days ) old guava

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 MATERIALS REQUIRED
 100 ml measuring flask

 Pestle and mortar

 Beaker ( 250 ml )

 Titration flask

 Funnel

 Burette

 Weight – box

 Pipette

 Filter paper

 Dilute H2SO4

 0.05 N KMnO4 solution

 Guava fruits at different stages of ripening

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RESULT

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 CONCLUSION

1) It is evident that guava fruit contains high amounts of Oxalate Ions ,

about 60 %

2) The percentage of Oxalate Ions in guava fruit was clearly found to be

increasing as it ripens .

3) The amount of Oxalate Ions is lowest when the fruit is fresh and highest
after 3 – 7 days from when it is plucked .

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 REFERENCE / BIBLIOGRAPHY

• NCERT LABORATORY MANUAL

• NCERT CHEMISTRY BOOKS

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