investigatory project of chemistry for class 12

1. KENDRIYA VIDYALAYA NO.2
SHIVAJI NAGAR, BHOPAL
CHEMISTRY
INVESTIGATORY PROJECT
SESSION:2018-2019
SUBMITTED TO:
MRS.JAGARATI SHARMA
SUBMITTED BY:
AISHWARY PATLE
XII ‘B’

2. CERTIFICATE:
This is to certify that Aishwary Patle , roll.no………….
,studying in class XII “B” of Kendriya Vidyalaya No.2,
Shivaji Nagar, Bhopal (M.P) has completed the
chemistry investigatory project under the guidance
and supervision of Mrs. Jagrati Sharma (PGT
Chemistry) in session 2018-2019.
PRINCIPAL TEACHER’S SIGN EXTERNAL

3. ACKNOWLEDGEMENT:
My sincere thanks to our chemistry teachers
Mrs.Jagrati Sharma for providing me all facilities
required for the completion of this project and who
supported me with gentle co-operation and great
patience.
I would also like to express my gratitude to our lab
assistantMr. Kemchand for his support during
making the project.
Aishwary Patle XII ‘B’

4. INDEX:
1. AIM
2. INTRODUCTION
3. REQUIREMENT
4. THEORY
5. PROCEDURE
6. OBSERVATION
7. RESULT
8. PRECAUTION
9. BIBLIOGRAPHY

5. AIM:
To compare the water soluble polyphone
(catechin) content in the various samples
of tea leaves.

6. INTRODUCTION:
India is a large exporter of tea which is a crash crop. Tea
is made from the young leaves and unopened buds of
the tea plants camellia. The use of an infusion of dried
tea leaves as a beverage has it origin since very ancient
times. It was first cultivated in china.
Tea leaf is rich in alkaloid caffeine which constitutes as
much as 4% of the dry matter in the young leaf. It is the
main active ingredient of tea which acts as a stimulant.
Besides caffeine, tea leaves contain tannin and colouring
matter polyphenolic compounds and some flavouring
agents. We can check the presence of all these
substances and their relative amounts through sample
experiments.

7. FACTORS AFFECTING THE QUALITY
OF TEA:-
The quality of tea depends on the climate and soil.
Climate: It is the deciding factor as to which variety of tea can be
grown to the best advantage. Change in the climate in the climate
affects the quality and flavor of tea and influences the time of
maximum seed fall. The tea plants best grow in the season of
monsoon land of South East Asia where cool whether if fairly dry
with a market fall in temperature. Frost kills the plants if the sum
reaches the affected area early in the morning before the leaf has
hard time to warm up. To prevent this tea plants are grown under
the trees.
Soil: Tea plants best grow on light loamy soil. However it can be
grown on all types of soil. Potash manure is very good. Nitrogenous
manures whether in organic form or chemical form have adverse
effect on the quality of the tea. Since soils contain such readily
available Aluminum and Magnese which the tea bush consumes
and stores in relatively large amounts, it is the need for these
elements that necessitates an acid soil for the growth of tea.

8. TYPES OF TEA:
TEA IN India is of two types:-
1. The Chinery type tea grows in and around Darjeeling and
yields a rich flavor.
2. The Assam type tea grows in the plants of Assam and West
Bengal and yields strong and bright liquored tea.
3. Aroma(smell) of tea: six hours after the leaf has been plucked,
the rapid development of asparagine’s takes place, irrespective
of whether physical withering has begun or not. Most of the
development of aroma takes place during fermentation and
reaches its optium stage in about 3 and half hours. The main
constituents responsible for aroma are:
>Caffeine
>Polyphenol
>amino acid
>Magnese and other inorganic materials

9. REQUIREMENT:
1. Beaker
2. Conical Flask
3. Funnels
4. Heating Arrangement
5. Tea bags of different brands of tea

10. PRINCIPLE:
Water soluble polyphenol are present up to
30%.They are very much soluble in water largely
responsible for the aroma (smell), color and quality
of tea samples.

11. THEORY:
Tea contains up to 30% of the water soluble
polyphenol (catechin). These are largely soluble in
responsible for the extent of these compounds in a
given sample, the tea leaves are immersed in hot
water for equal time and the loss in the weight of
tea leaves is determined.

12. PROCEDURE:
1. Weigh exactly 5g of the different samples of tea
and place them in tea bags.
2. Take three or four conical flasks and put 100ml of
hot water to each of them.
3. Put tea bags of different samples of tea in the
different conical flasks. After 10 minutes remove
the bags and dry them by placing in an oven.
4. When tea bags become dry, reweight them.
5. Note the flavor of the tea solution obtained.

13. OBSERVATION:
s.no Brand
Name
of Tea
Initial
Weight
[X g]
Final
Weight
Loss of
weight
[Y g]
% of water
Soluble
Component=
Y/X
1.
2.
3.
4.

14. RESULT:
The polyphenol content is more in ……………………….
The polyphenol content is more in the tea which gives
the better flavor.

15. PRECAUTIONS:
1. Students should wear lab coat.
2. Handle apparatus with care.
3. Do not touch beakers while heating.
4. Do not use large amount of substance.
4. Never taste anything.
5. Wash your hands before leaving the lab.

16. BIBLIOGRAPHY:
1. WIKIPEDIA.COM
2. GOOGLE SEARCH ENGINE
3. CHEMISTRY COMPREHENSIVEMANUAL OF
CLASS XII