Chemistry project work

By: Shreya RajpalAbhinav Public School, Delhi

Class: 12 th Science Certificate

This is to certify that Shreya Rajpal of class XII science of Abhinav Public School, Delhi has completed his demonstration file under the supervision of Mr. Yadvendra Singh. She has taken proper care and shown utmost sincerity in the completion of this file.

I certify this file is up to my expectations and as per the guidelines issued by C.B.S.E.

Mr. Yadvendra Singh

Signature

Project Report On

Determination of the Oxalate Content in Guava Fruit

ACKNOWLEDGEMENTI express my deep sense of gratitude to my teacher Mr. Yadvendra Singh for his valuable guidance, inspiration and help provided in every aspect if this project.

I am thankful to him for his constant evaluation of the project.

Last but not the least, I extend my sincere thanks to my School, Assistant, and Friends, who played an important role in proper tunings of my project.

Shreya Rajpal

12 th Science

EXPERIMENTAIM:

Guava is mainly a winter fruit. It has medicinal properties and is cultivated in almost every part of India. Approximate composition of this fruit is:

Constituents % Amount

    Water 76.10Protein 1.50Fats 0.20Calcium 0.01Phosphorus 0.04Vitamin “C” 0.03Organic matter 14.50

Guava a fruit that contains maximum amount of Vitamin C, after Amala but amount of Vitamin C decreases with the ripening of Fruits.Vitamin C gets converted into oxalate with ripening of fruit. Thus amount of oxalate in the fruit is a reflection on the amount of Vitamin C in the fruit and its determination. Therefore, makes an important study.

OBJECTIVE:

Determination of the oxalate ions in guava fruit at different stages of its ripening.

THEORY:

Oxalate content of fruit is made into the solution by boiling its pulp with distilled water and its amount in the solution in determined by redox titration using potassium permagnate (KMnO4) solution.

• Transfer the pulp obtained into a 250ml beaker. Wash the pestle and mortar well with about 100ml of water and transfer the washing also into the beaker.

• Boil the contents in the beaker for about 10 minutes. Cool and filter through a funnel. Collect the filtrate in a 250ml measuring flask. Make the volume up to the mark i.e. 250 ml by adding Distilled water. Label the

flask as "Ripe guava solution".

• Similarly, prepare 250 ml solution of 25g Semi Ripe, Raw Guava.

• Now, Pipette out 10 Ml of Solution from one of the flask into a conical flask. Add 10 Ml of Dilute H2SO4 to it. Warm the flask about 60 degree Centigrade and titrate it with 0.05M KMnO4 Solution until the colour of the solution just changes to permanent Pink. Repeated the experiment with same solution till three concurrent readings are obtained.

• Similarly, find out the amount of 0.05M KMnO4 consumed for 10 Ml of three guava solutions. The guava solution which consumes maximum volumes of per magnate solution obtains maximum oxalate ions.

• Compare the three titre value i.e. volume of KMnO4 consumed for 10ml of the three guava solutions. The Guava solution contains maximum oxalate Ions.

NOTE:

The amount of oxalate ion present in the solution i.e. Fruit can be calculated quantitavely also. For this first standardizes the KMnO4 solution by titrating it against standard oxalic acid solution. Then calculate the amount of oxalate ions by applying N1V1=N2V2 and Strength = Equivalent Weight X N equation.

OBSERVATION:Molarity of the KMnO4 Solution=0.05 MEnd point = Colourless to pink.Volume of guava solution Taken each time for titration=10 ML.

GuavaSolution

BurettingInitial

ReadingFinal

Volume ofKmNo4

Concurrent Reading

(ML)Ripped Guava      

Semi Ripped Guava        

Raw Guava        

CONCLUTION:

The amount of oxalate ions increases with the ripening of Guava.

PRECAUTIONS:

• Do not mix three fruits or their Solutions.

• Boiled the crushed fruit with equal amount of water and for the same length of time in all cases.

• Wash the pestle and mortar well before after every use.

• Weighing should be done accurately and carefully.

BIBLIOGRAPHY

• Wikimedia.org

• Chemistry, Lab Manual for Class 12 th • Comprehensive's chemistry