chem proj (1)

Chemistry project work 

By: Shreya Rajpal Abhinav Public School, Delhi th

Class: 12 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 

 ACKNOWLEDGEMENT   I express my deep sense of gratitude to my teacher Mr. Yadvendra Singh for his  valuable guidance, inspiration 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 

EXPERIMENT    AIM: 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 

76.10 

Protein 

1.50 

Fats 

0.20 

Calcium 

0.01

Phosphorus 

0.04 

Vitamin ´Cµ 

0.03

Organic 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    solution.  potassium permagnate (KMnO 4 4 ) 

 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 H 2 SO  SO 4 4  to it. Warm the flask about 60 degree  Centigrade and titrate it with 0.05M KMnO 4 4  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 KMnO 4 4  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 KMnO 4 4  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 KMnO 4 4  solution by titrating it  against standard oxalic acid solution. Then calculate the amount of oxalate ions by  applying N 1V 1=N 2 2 V  V2 2   and Strength = Equivalent Weight X N equation.

OBSERVATION: Molarity of the KMnO 4 4  Solution=0.05 Solution=0.05 M  End point = Colourless to pink. Volume of guava solution Taken each time for titration=10 ML.

Guava  Solution  Ripped   Guava  Semi Ripped Guava  Raw  Guava 

Buretting  Initial  

Reading  Final  

Volume of   KmNo4 

Concurrent  Reading (ML) 

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 Comprehensive's chemistry