Chemistry investigatory project on contents of different chocolates in the market
The chocolate sample tested positive for sugar, fat, protein and calcium but no presence of iron, magnesium and nickel was detected.
2. 2
Army Public School
Barrackpore
Name: Shubhrajit Sadhukhan
Class: 12D
Subject: Chemistry
Topic: Contents of different chocolates in the market
Roll:
Session: 2022-23
4. 4
Certificate
This is to certify that Shubhrajit
Sadhukhan student of class 12D, has
successfully completed the project work in
fulfillment of the chemistry practical
examination conducted by AISSCE,
New Delhi.
Signature of Internal Examiner Signature of External Examiner
5. 5
Self-Certificate
This is to certify that I, Shubhrajit
Sadhukhan of class 12D of Army Public
School Barrackpore, have solely and
exclusively done this investigatory
project with assistance from my
teacher and the web.
The basis of the project has been put
together on bona fide grounds and
the allied information is genuine.
Signature of Student
6. 6
Intro
Chocolates have become one of the most popular foodstuffs in
the world today. Apart from being consumed as confectionaries,
they are used in beverages and as a flavoring agent in cakes,
candies, chips, etc. Chocolates are made from cocoa/cacao seeds
that are fermented, dried and grounded to powder, made runny
with milk and sugar, and then hardened in the form of bars. A
100 g chocolate bar contains around 50 g sugar, 30 g fat, 5 g
protein, and traces of calcium. A person with a sweet tooth
consumes over 4kg of chocolate annually. Heavy metals are
potentially hazardous contaminants in chocolates.
7. 7
Experiment
Aim: To find out the presence of proteins, fats, sugars, calcium
and heavy metals in chocolate samples.
Chemicals used:
Sodium hydroxide (NaOH)
Copper sulphate (CuSO4)
Moliscli’s Reagent (C10H7OH)
Fehling’s Solution A & B
Sulphuric acid (H2SO4)
Tollen’s Reagent
Ammonium Chloride (NH4Cl)
Ammonium Hydroxide (NH4OH)
Sodium Phosphate (Na3PO4)
Apparatus:
Test Tube
Test Tube Holder
Watch glass
Burner
Glass rod
Tripod stand
8. 8
Procedure Observation Inference
Tollen’s reagent is added to sample
and made to stand in water bath
Forms silver
mirror
surface
Sugar
present
To 5 ml of sample, 1 pellet of NaOH
is added followed by 1-2 drops of
CuSO4 sol.
Violet
coloration
Protein
present
A piece of filter paper is crushed
with the sample and taken over
flame
Translucent
spot around
the sample
Fat present
A mixture of NH4OH and
(NH4)2CO3 is added to the sample
White ppt. Calcium
present
A drop of conc. HCl is added to
sample on a watch glass and the
paste is taken over spirit lamp with
a glass rod
Brick-red
flame
Calcium
present
NH4Cl + NH4OH mixture is added to
sample
No ppt. Iron absent
NH4Cl + NH4OH + Na3PO4 mixture
is added to sample
No ppt. Magnesium
absent
NH4Cl + NH4OH mixture is added to
sample and H2S is passed
No ppt. Nickel absent
9. 9
Conclusion
The chocolate sample tested positive for sugar, fat, protein and
calcium but no presence of iron, magnesium and nickel was
detected.
11. 11
Acknowledgement
I would like to express my sincere regards to my chemistry
teacher, Mrs. Anindita Roy for assigning me this project
and motivating me to complete it.
Also, I would also like to extend my thanks to my parents
for the provision of all the necessary resources and to my
friends for their sincere help.
