Study Of The Presence Of Oxalate Ion Content In Guava Fruit At Different stages of ripening.

1. CHEMISTRY PROJECT :-
Study Of The Presence Of Oxalate Ion Content In Guava Fruit At
Different stages of ripening.
Submitted by: - Pratibha Singh
Class: - XII (A)
Roll No. :- 38
Submitted to :- Mr. B.N Gupta

4. S.NO. TOPIC
1. INTODUCTION
2. BENEFITS AND USES OF GUAVA
3. PROPERTIES / ACTION DOCUMENTED BY
RESEARCH
4. FOOD VALUE PER 100g OF EDIBLE PORTION
5. ACID BASE TITRATION
6. REDOX TITRATION
7. TO STUDY THE PRESENCE OF OXALATE ION IN
GUAVA FRUIT AT DIFFERENT STAGES OF
RIPENING

5. INTRODUCTION
Guava or psidum guajava is one of the various mystaceous trees or
shrubs of the genus psidum. When ripe, it has dark or light yellow
on light yellow on ripening , the pulp of the embedded in it.
Guava has the highest percentage of Vitamin C among all citrus
fruit. It also contains oxalates, among of which varies during
pipening of fruit. During the process of removal of two equivalent
hydrogen of vitamin C . (Ascorbic Acid) molecules take place .
Dehydroascorbic acid is further oxidized to oxalic acid in alkaline
medium.

6. BENEFITS AND USES OF GUAVA
1. Guavas are an excellent source of vitamin C and also contain
iron, calcium, and phosphorus. The guava fruit contain the
highest vitamin C content out of all citrus fruits as much as
180 mg per 100g of fruit.
2. Older children and adults, a cup once or twice daily of a leaf
decoction is the tropical herbal medicine standard.
3. A guava leaf decoction is taken to relieve colds and
bronchitis.
4. The roots, bark, leaves and immature fruits because of their
astringency, are commonly employed to halt gastroenteritis,
diarrhea, dysentery and vomiting in cholera patients.
5. It also has hypoglycemic and anti bacterial properties. The
fruit, when eaten whole helps reduce both, high blood
pressure and cholesterol level .
6. Guava benefits in battling diabetes, combats cancer and
protect prostate.
7. Guava can improve heart health by helping to control blood
pressure and cholesterol.
8.Guava is highly effective in removing constipation.

7. PROPERTIES / ACTIONS DOCUMENTED
BY RESEARCH
Guava fruit acts as a : Amebicide , analgesic ( pain
reliever), antibacterial , anticandidal, antidysenteric,
antifugal, antimalarial, antioxidant, antispasmodic,
antiulcerous, cardio depressant, cardiotonic (tones, balances,
strengthens the gastric tract), hypotensive (lower blood
pressure), sedative , vasoconstrictor).
Other properties / Actions Documented By
Traditional Use
Guava fruit also has the following effects on human health:
Anti-anxiety, anticonvulsant, antiseptic, astringent, blood
cleaner, digestive stimulant, menstrual stimulant, neervine
(balances/ calms nerves) , vermifuge (expels worms).

9. ACID BASE TITRATION
When an acid base reaction is used , the process is acid-base
titration. When a redox reaction is used the process is called a
redox titration. Titration is also called volumetric analysis , which
is type of quantitative chemical analysis.
Titation is a laboratory technique by which we can determine the
concentration of an known reagent using a standard concentration
of another reagent that chemically reacts with the unknown. This
standard solution is referred to as the “titrant” . We have to have
some way to determine , when the reaction is complete that we are
using . This is referref to as the “end point” or more technically
the equivalence point . At that point , the entire unknown has been
reacted with the standard titrant and some kind of chemical
indicator must let us know when that point has been arrived at.

10. Generally , we know the Normality of the titrant since it is a
standard solution. We also pre-measure the volm of the unknown.
We then titrate with the standard from a burette into the
container with the measured unknown and the chemical indicator
either turns color or a precipitates indicates that the end point or
the equivalence point has been reched. Having the initial and final
readings of titrant burette gives us the volume of the titrant used.
The only unknown in the equation is the Normality of the
unknown.
Molarities of acidic and basic solution are often used to convert
back and forth between moles of solutes and volumes of their
solutions, but how were of solutes and volumes of their solutions, but
how were the molarities of these solutions determined? This section
describes a procedure called titration, which can be used to find the
molarity of a solution of an acid or a base.
In titration, one solution is added to another until a chemical
reaction between the components in the solutions has run to

11. completion. Solution 1 is called the titrant, and we say that it is
used to titrante solution 2.
The completion of reaction is usually shown by a change of a
substance that reacts with the solute in solution 2 is added to a
burette . This solution in the burette, which has a known
concentration, is the titrant. The burette is set up over the
Erlenmeyer flask so the titrant can be added in a controlled
manner to the solution to be titrated. For example a 0.115 M
NaOH solution might be added to a burette, which is set up over
the Erlenmeyer flask containing the nitric acid solution.

12. REDOX TITRATIOn
Redox titration is a type of titration based on redox reaction
between the type of titration based on a redox reaction
between the analyte and titrant.
It is a titration of a reducing agent by an oxidizing
agent between the analyte and titrant.
Redox reaction may involve the use of a redox indicator.
This experiment involves the use of potassium
permanganate which is the oxidizing agent as well as the
indicator.
This experiment involves the use of potassium
permanganate which is the oxidizing agent as well as the
indicator.
Permanganate ion is a powerful oxidizing agent,
especially in acidic solution, which can be used to analyze (by
titration) solution containing many different species. In these

13. titration reactions, the intensely colored MnO-4
ion is
reduced to form the colorless Mn+2
ion.
As advantage of using the permanganate ion in the
titration of colorless unknown solutions is that it is “self
indicating”.As long as the reducing agent remains present in
the sample, the color of MnO-4
quickly disapperars as it is
reduced to Mn+2
.
However , at the endpoint, all the reducing agent has
been up so the next drop of MnO-4
solution is sufficient to
cause an easily detechted color change, colorless ( faint,
permanent peach/pink). So we know that at the endpoint,
the oxidizing agent (MnO-4
) and reducing agent ( H2O2
or Fe+2
) have reacted in exactly in proportion to their
stoichiometry in the balance redox equation . If we know how
much of the oxidizing agent we added, then we can figure out
exactly how much reducing agent was present in the
unknown!

14. To study the presence of
oxalate ion in guava fruit at
different stages of ripening
Requirement- 100ml measuring flask, pestle
and mortar , beaker, titration flask , funnel , weight box,
filter paper, dilute H2SO4 – N20 KMnO4 , guava
fruit at different stages of ripening.
Theory- Oxalate ions are extracted from fruit by
boiling pulp dil. H2SO4 . Then oxalte ion are estimated
volumetrically by titrating the solution with standard
KMnO4 solution.

15. OBSERVATION-
Weight of guava fruit taken each time =50.0gram
Volume of guava extract taken in each titration = 20.2ml
Normality of KMnO4 solution = 1/20
OBSERVATION TABLE

16. The stenght of guava fruit at
different stages of ripening-
Guava extract from strength
Fresh 1.056 g / Liters
One day old 0.902g/liters
Two days old 0.792g/liters
Three days old 0.66g/liters
Result:
It is concluded from above experiment that the amount of
oxalate ion in guava at different stages of ripening decreses.

17. Precautions:
1. The apparatus must be clean.
2. Hndle acid with care.
3. Balance should be accurate.
4. Mix the content well.
5. Take reading of lower meniscus.

18. CERTIFICATE
This is to certify that this project is submitted by
Pratibha Singh student of class XIIth
A in acadmic
year 2018-2019 of Shivalik Cambridge College and
given satisfactory account of it .
Date:
Teacher principal
(signature) (signature)