Chem Invg Prj (oxalate content in guvava)

8/9/2019 Chem Invg Prj (oxalate content in guvava)

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KENDRIY VIDY L Y SIV G NG

2014 2015

CHEMISTRY PROJECT REPORT

ON

STUDY OF THE OX L TE ION CONTENT IN GU V FRUIT

Submitted to

CENTR L BO RD OF SECOND RY EX MIN TION

in fulfilment of AISSCE - 15

Under Guidance of,

Shri. V. Ramesh Pandian

PGT (CHEM)

KV Sivaganga

Prepared by,

R. Rahul

XII (SCIENCE)

KV Sivaganga


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CERTIFICATE

This is to certify that R. Rahulof class

12thhas satisfactorily completed the

project To Study the Presence of Oxalate

ion content in Guava fruit

I have examined the project and hereby

accord my approval of it as a study

carried out and presented in the manner

required for its acceptance. This does

not necessarily endorse or accept every

statement made or opinion expressed or

conclusion drawn, but only signifies the

acceptance of the project for the purposeit is submitted for.

This project may be considered as a part

of fulfillment of AISSCE conducted by

CBSE.

Internal Examiner External Examiner


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ACKNOWLEDGEMENT

It is my utmost pleasure to express deep sense of gratitude towards

Shri V Ramesh Pandian, my Chemistry teacher, who directed me to

complete this project successfully. His valuable guidance and

supervision are considerably responsible for helping this project attain

its present form. I am also thankful to my dear friend for accompanying

me in this work as fellow team member. Without his support, this

project wouldnt have been successfully completed.

Once again I wish to thank all my friends and teachers who involved in

making of this project.

Thank you!!!


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CONTENTSS.no Title Page No.

1 Introduction 1

2 Experiment 2 - 9

Aim 2

Apparatus Required 3

Chemicals Required 3

Materials Required 3

Theory 4

Chemical Equations 5

Procedure 6

Observation 7

Calculation 8

Result 9

3 Conclusion 10

4 Bibliography 10


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INTRODUCTION

Guava is sweet, juicy and light or dark green coloured fruit. It is cultivated in

all parts of India. When ripe it acquires yellow colour and has penetrating

strong scent. The fruit is rich in vitamin C and minerals. It is a rich source of

oxalate and its content in the fruit varies during different stages of ripening.

Guava fruit, usually 4 to 12 cm long, are round or oval depending on thespecies. The outer skin may be rough, often with a bitter taste, or soft and

sweet. Varying between species, the skin can be any thickness, is usually

green before maturity, but becomes yellow, maroon, or green when ripe.

Guava fruit generally have a pronounced and typical fragrance, similar

to lemon rind but less sharp. Guava pulp may be sweet or sour, off-white

("white" guavas) to deep pink ("red" guavas), with the seeds in the central

pulp of variable number and hardness, again depending on species

WHAT IS OXALATE?

Oxalate is an organic acid, primarily found in plants, animals and humans. It

is not an essential molecule and is excreted from our body in an unchanged

form. Our body either produces oxalate on its own or it converts other

molecules like vitamin C to oxalate. External sources like the foods we eat

also contribute to the accumulation of oxalate in our body. The oxalate presentin the body is excreted in our urine as a waste. Too much of oxalate in our

urine, results in a medical condition called as hyperoxaluria, commonly

referred to as kidney stones. Diet is looked upon as a preventive measure in

addition to medicines to treat kidney stones. Read more on what causes

kidney stones.


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IM

To test for the presence of oxalate ions in the

guava fruit and how its amount varies during

different stages of ripening.


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APPARATUS REQUIRED

1.100 ml measuring flask

2.Pestle & Mortar

3.Beaker

4.Burette

5.Funnel

6.

Weighing machine7.Filter Papers

CHEMICALS REQUIRED

1.dil. H2SO4

2.KMnO4solution

MATERIALS REQUIRED

1.Guava Fruits at different stages of ripening


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THEORY

Oxalate ions are extracted from the fruit by boiling pulp with dil. H2SO4. Then

oxalate ions are estimated volumetrically by titrating the solution with

standard KMnO4solution.

Titration is a common laboratory method of quantitative chemical

analysis that is used to determine the unknown concentration of a

known reactant. Because volume measurements play a key role in titration, it

is also known as volumetric analysis. A reagent, called the titrant or titrator, of

a known concentration (a standard solution) and volume is used to react with a

solution of the analyte or titrand, whose concentration is not known. Using a

calibrated burette or chemistry pipetting syringe to add the titrant, it is

possible to determine the exact amount that has been consumed whenthe endpoint is reached. The endpoint is the point at which the titration is

complete, as determined by an indicator (see below).

This is ideally the same volume as the equivalence pointthe volume of

added titrant at which the number of moles of titrant is equal to the number of

moles of analyte, or some multiple thereof (as in polyprotic acids). In the

classic strong acid-strong base titration, the endpoint of a titration is the point

at which the pH of the reactant is just about equal to 7, and often when the

solution takes on a persisting solid colour as in the pink of

phenolphthalein indicator.


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CHEMICAL EQUATIONS

Molecular Equations

2KMnO4 + 3H2SO4 K2SO4+ 2MnSO4+ 2H2O + 4[O]

HOOC-COOH.2H2O +[O] C

o7060

2CO2+ 2H2O x 5

3KMnO4+ 3H2SO4+5 HOOC-COOH.2H2O

K2SO4+ 2MnSO4+ 18H2O + 10CO2

Ionic Equations

MnO4- +16H++ 5e- Mn2++ 4H2O x 2

C2O4 2CO2+ 2e- x 5

2MnO4-+ 16H++ 5C2O42- 2Mn2++8H2O + 10CO2


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PROCEDURE

1.Weighed 50 g of fresh guava and crushed it to a fine pulp using

pestle and mortar.

2.Transferred the crushed pulp to a beaker and added about 50 ml

dilute H2SO4 to it.

3.Boiled the content for about 10 minutes. Cooled and filtered the

contents in a 100 ml measuring flask.

4.Made up the volume 100 ml by adding ample amount of distilled

water.

5.

Took 20 ml of the solution from the flask and added 20 ml of dilute

sulphuric acid to it.

6.Heated the mixture to about 600 C and titrated it against (n/10)

KMnO4 solution taken in a burette till the end point had an

appearance of pink colour.

7. Repeated the above experiment with 50 g of 1day, 2 day and 3 day

old guava fruits.


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CALCULATIONS

For fresh guava

N1V1 = N2V2

(guava extract) (KMnO4 solution)

N1 x 10 =1

20 x

Normality of oxalate, N1= 200

Strength of oxalate in fresh guava extract

= Normality x Eq. mass of oxalate ion

=

200x 44 g/litre of the diluted extract

For One day old guava

N1V1 = N2V2

(guava extract) (KMnO4 solution)

N1 x 10 =1

20 x

Normality of oxalate, N1=

200

Strength of oxalate in one day guava extract

= Normality x Eq. mass of oxalate ion

=

200x 44 g/litre of the diluted extract

Similarly, calculate the strength of oxalate in 2 days old guava extract

and interpret the result.


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RESULT The strength of oxalate of fresh guava =

The strength of oxalate of one day old guava =

The strength of oxalate of two day old guava =


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CONCLUSION

BIBLIOGRAPHY

1.Comprehensive Lab Manual for Chemistry

2.

Wikipedia3.cbse.nic.in/academic.html

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Chem Invg Prj (oxalate content in guvava)