This document describes a chemistry project to analyze the constituents of two alloys - brass and bronze. The project aims to increase understanding of alloy analysis through hands-on experience. Specific objectives are to analyze the constituents of brass, which contains copper and zinc, and bronze, which contains copper and tin. The document outlines the required materials, relevant theory, procedure and observations for testing samples of each alloy to identify the present metals through formation of characteristic precipitates and color changes.

1. CHEMISTRY
PROJECT
AIM- Study Of
Constituents Of An
Alloy
NAME-HIMANSHU RAWAT
CLASS -12​TH
1

2. CONTENTS PAGE N​0.
1.ACKNOWLEDGEMENT 3/1​6
2.CERTIFICATE 4/16
3.INTRODUCTION 5​/1​6
4.AIM OF THE
EXPERIMENT
6​/1​6
(i)GENERAL
OBJECTIVES
(ii)SPECIFIC
OBJECTIVES
5.MATERIAL REQUIRED 7​/1​6
6.THEORY 8​/1​6
7.PROCEDURE AND
OBSERVATIONS
1​2​/1​6
8.CONCLUSION 15​/1​6
9.BIBLIOGRAPHY 16​/1​6
2

3. Acknowledgement
I would like to express my
special thanks of gratitude to my
teacher ​Mrs. kumkum bansal
mam​ who gave me the golden
opportunity to do this wonderful
experiment to get information
about constituent of an alloy ,
which also help me in doing a lots
of research and I came to know
about so many new things I am
really thankful to them. secondly,
I would also like to thank my
parents and friends who helped
me a lot in finalising this project
within the limit time frame.
3

4. ​CERTIFICATE
This is to certify that the
chemistry project title
“​Study of constituent of an Alloy​”
has been successfully completed
by Himanshu Rawat of class 12th
in partial fulfillment of Curriculum
of Central Board of Secondary
Education (CBSE) leading to the
award of annual examination of
the Year 2018-2019.
SIGNATURE OF EXTERNAL SIGNATURE OF CHEMISTRY
EXAMINER TEACHER
4

5. INTRODUCTION
An alloy is a homogeneous
mixture of two or more metals or
a metal and non-metal. They are
generally harder than their
components with reduced
malleability and ductility. Alloys
are prepared to enhance certain
characteristics of the constituent
metals, as per requirement. In
this project, we shall qualitatively
analyze the chemical composition
of two alloys: Brass and Bronze
5

6. AIM OF THE EXPERIMENT
(i)General objective:-
This project is being carried out
with a view to increase the
appreciation of alloy analysis as
an important branch of chemistry.
The hands-on laboratory
experience gained is highly
beneficial in understanding the
general procedure of qualitative
analysis of an unknown sample.
(ii)Specific objective:-
In this project, we shall be
analyzing the constituents of
Brass and Bronze.
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7. Materials Required
1) Brass and Bronze pieces
2) China dishes
3) Filtration apparatus
4) Nitric acid
5) Hydrogen sulphide gas
6) Ammonium hydroxide
7) Ammonium chloride
8) Potassium ferrocyanide
9) Ammonium sulphide
10) Dil hydrochloric acid
11) Mercuric chloride
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8. THEORY:-
Brass
Brass contains Cu and Zn . Both
dissolve in nitric acid.
​4Zn+ 10 HNO​3​= 4Zn(NO​3​)​2​+ N​2​O + 5H​2​O
3Cu + 8HNO​3​= 3Cu(NO​3​)​2 ​+ 4H​2​O+2NO
Further analysis is carried out for
respective ions.
Cu dissolves in H​2​S to give black
ppt. of CuS. It is filtered to get the
soln of Zinc Sulphide. It
precipitates out in the form of
ZnCl​2​ in an ammoniacal solution
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9. of Ammonium chloride. The
precipitate is dissolved in dilute
HCl and then treated with
Potassium ferrocyanide to get a
bluish white ppt. of Zn​2​[Fe(CN)​6​].
Bronze
Bronze contains Cu and Sn.
Their nitrates are obtained by
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10. dissolving the sample in conc.
Nitric acid. The nitrates are
precipitated as sulphides by
passing H​2​S through their
solution in dil. HCl.
The CuS is insoluble in yellow
ammonium sulphide, while SnS is
soluble. The ppt. is separated by
filtration.
The ppt. is dissolved in conc.
HNO​3​ and then Ammonium
hydroxide solution is passed
through it.Blue colouration
confirms the presence of Cu. The
filtrate is treated with conc. HCl
followed by Zinc dust to obtain
10

11. SnCl​2​ . Then HgCl​2​ solution is
added. Formation of
slate-coloured ppt. indicates the
presence of Sn.
SnS​2 ​+HCl(conc.)= SnCl​4 ​+ H​2​S
SnCl​4​ +Fe = SnCl​2​+FeCl​2
SnCl​2​ + HgCl​2​ = Hg​2​Cl​2​ + SnCl​4
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12. Detail of Procedure &
Observations
Brass:
1. A small piece of brass was
placed in a china dish and
dissolved in minimum quantity of
50%conc.HNO​3​.
2. The soln. was heated to obtain
a dry residue. The residue was
dissolved in Dilute HCl.
3. H​2​S gas was passed and a
black.ppt. was observed. The
soln. was filtered and the ppt.
was dissolved in NH​4​OH solution.
A blue coloration observed
indicates the presence of Cu.
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13. 4. The filtrate was tested for
presence of Zn. Ammonium
hydroxide and chloride solutions
were added and then H​2​S gas
was passed.
A dull grey ppt. was separated
and dissolved in dil. HCl followed
by addition of Potassium
ferrocyanide. A bluish white ppt.
confirms the presence of Zn.
Bronze:
1. The sample was dissolved in
50% HNO​3​ and then heated to
obtain nitrates.
13

14. 2. The nitrates were dissolved in
dil. HCl and then precipitated as
sulphides by passing H​2​S gas.
3. The precipitates were treated
with yellow amm.sulphide when a
part of it dissolves. The soln. was
filtered.
4. The ppt. was tested for Cu as
in the case of brass.
5. The filtrate was treated with
conc. HCl followed by Fe dust.
6. Then HgCl​2 ​soln. was added.
Formation of a slate-coloured ppt.
confirmed the presence of Sn.
14

15. Conclusion
​Brass contains Copper and Zinc.
Bronze contains Copper and Tin.
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16. Bibliography
1. Comprehensive Practical Book
of Chemistry- Class 12​TH​
.
2. NCERT Inorganic Chemistry
chapters.
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