Investigatory project (2016 - 17) XII Std
ALAGU JOTHI ACADEMY
(AN INTERNATIONAL STANDARD CBSE SR. SEC. SCHOOL)
(Affiliated to CBSE – New Delhi)
No. 3 Melaiyur, Karuvazhakkari post,
Poompuhar Road, Nagai Dist. 609 304
CLASS XII
DEPARTMENT OF CHEMISTRY
2016 - 2017
ALAGU JOTHI ACADEMY
(AN INTERNATIONAL STANDARD CBSE SR. SEC. SCHOOL)
(Affiliated to CBSE – New Delhi)
No. 3 Melaiyur, Karuvazhakkari post,
Poompuhar Road,
Nagai Dist. 609 304
DEPARTMENT OF CHEMISTRY
CHEMISTRY INVESTIGATORY PROJECT
2016-17
REG NO:
This is certified to be the Bonafide record of work done by _______________________ of class ________ in the chemistry lab of the school during the year 2016-2017.
Submitted for the ALL INDIA SENIOR SECONDARY CERTIFICATE EXAMINATION held on ______________ at ___________________________.
Principal Teacher In charge
Internal Examiner External Examiner
CERTIFICATE OF AUTHENTICITY
This is to certify that Miss. S. Sunetha, student of Class XII of Alagu Jothi Academy, An International Standard CBSE
Sr. Sec. School, Mayiladuthurai, Nagapattinam District has completed the Investigatory Project on topic " STUDY OF OXALATE ION CONTENT IN GUAVA" Under my guidance. This project is absolutely genuine and does not contain of any plagiarized materials. The references taken in this project have been declared at the end of this report.
ACKNOWLEDGEMENT
With immense pleasure, I extent my heartful thanks to those who help me to go a long way in the completion of this investigatory project.
I also express my gratitude to Mrs. S. Menaga, Chemistry teacher, without her valuable guidance it would have been impossible to complete my project work.
I am also thankful to my parents, whole staff of the school for their timely help. I also thank my Principal Mr. C. Noel Mani for his immense cooperation.
Above all I thank Almighty who is always there to help me.
INDEX :
Aim
Introduction
Thoery
Requirements
Procedure
Precautions
Observations
Calculations
Result
Conclusion
AIM:
To study the presence of oxalate ions in guava fruit at different stages of ripening.
INTRODUCTION:
Guava :
Guava is a common sweet fruit found in India and many other places around the world.Guavas are plants in the Myrtle family (Myrtaceae) genus Psidium (meaning "pomegranate" in Latin), which contains about 100 species of tropical shrub. On ripening it turns yellow in color. Rich in vitamin C, this fruit is a rich source of oxalate ions whose content varies during the different stages of ripening. Guavas have a pronounced and typical fragrance, similar to lemon rind but less in strength.
Oxalate :
It is a carboxylic acid, primarily found in plants and animals. It is not an essential molecule and is excreted from our body, unchanged. Our body either produces oxalate on its own or converts other molecules like Vitamin C to oxalate. External sources like food also contribute to the accumulation of oxalate in our body.The oxalate present in the body is excreted in the form of urine as waste. Too much of oxalate in our urine results in a medical condition called, commonly referred to as kidney stones. Diet is looked upon as preventive measure in addition to medication to treat Kidney stones.
THEORY :
Oxalate ions are extracted from the fruit by boiling pulp with dilute H2SO4.The oxalate ions are estimated volumetrically, by titrating the solution with KMnO4 solution .A reagent, called the titrant, of a known concentration (a standard solution) and volume is used to react with a solution of the analyte or titrant, 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 when the endpoint is reached. The endpoint is the point at which the titration is complete, as determined by an indicator. This is ideally the same volume as the equivalence point. The 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. 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 to7, and often when the solution takes on a persisting solid colour as in the pink of phenolphthalein indicator.
Chemical equation
REQUIREMENTS :
APPARATUS REQUIRED
100ml measuring flask
Pestle and mortar
Beaker
Burette
Funnel
Weighing machine
Filter papers
CHEMICALS REQUIRED
Dil.H2SO4
Potassium permanganate solution (KMno4)
Guava fruits at different stages of ripening.
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 content sin 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 60oC and titrated it against 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.
PRECAUTIONS:
1.There should be no parallax while taking measurements.
2.Spillage of chemicals should be checked.
3. Avoid the use of burette having a rubber tap as KMnO4 attacks rubber.
4.In order to get some idea about the temperature of the solution touch the flask with the back side of your hand.When it becomes unbearable to touch, the required temperature is reached.
5.Add about an equal volume of dil. H2SO4 to the guava extract to be titrated (say a full test tube) before adding KMnO4
6.Read the upper meniscus while taking burette reading with KMnO4 solution.
7. In case, on addition of KMnO4 a brown ppt. appears, this shows that either H2SO4 has not been added or has been added in in sufficient amount. In such a case, throw away the solution and titrate again.
OBSERVATIONS:
1.Weight of the guava fruit for each time was gm
2.Volume of guava extract taken for each titration was ml
3.Normality of KMnO4solution was
4.Colour Changes to pink
CALCULATIONS:
1)For raw guava :
N1V1 = N2V2
N1 x 10 = (1/10) x
1/10 x Normality of oxalate =(x/100) = strength of oxalate in fresh guava extract = normality x Eq. mass of oxalate ion
= of diluted extract
=
2)For semi ripened guava ( 1 day old):
Strength of oxalate in one day old guava extract
= of diluted extract.
=
3)For ripened guava:
Strength of oxalate in fresh guava extract
= of diluted extract
=
RESULT:
(A)The normality of oxalate ions of :
1.Fresh guava solution is = ml
2. Semi-ripen guava solution is = ml
3.Ripened guava solution is = ml
(B)The strength of oxalate ions of :
1.Fresh guava solution is = ml
2.Semi-ripened guava is = ml
3.Ripened guava is = ml
CONCLUSION:
The content of oxalate ions in guava was found to be per cent, which is close to the literature value of percent. It was also noticed that the content of oxalic ions grows with ripening of guava.
BIBILOGRAPHY:
www.google.com
www.wikipedia.com
www.reader.google.com
www.labs.google.com
www.quora.com
