coin investigatory)
TRANSCRIPT
Chemistry Project
On Coin Analysis
Prepared By:Saumya KharyaXII – ASession : 2011-2012Board Roll Number :Father Agnel School
AIM
Qualitative Analysis
Of Different
Coins
CERTIFICATE
This is hereby to certify that, the original and genuine investigation work has been carried out to investigate about the subject matter and the related data collection and investigation has been completed solely, sincerely and satisfactorily by Saumya Kharya of Class-XII,Father Agnel School, regarding her project titled “Qualitative Analysis of Coins”.
Teacher’s Signature
ACKNOWLEDGEMENT
It would be my utmost pleasure to express my sincere thanks to My Chemistry Teacher Mrs. Jyoti Verma, in providing a helping hand in this project. Her valuable guidance, support and supervision all through this project titled “Qualitative Analysis of Coins”, is responsible for attaining its present form.
Saumya
XII
PURPOSE
I was interested in finding out the contents of the coins we use in everyday life money transactions. Humans have been using coins since their invention in 700 B.C. for trading of goods and services.
Another fact which inspired me to do this project is that I am in touch with qualitative analysis whose knowledge with other factors helped me to do so.
CONTENTS
Introduction
Theory
Apparatus
Chemicals Required
20 Paise Coin(India)
1 Cent Coin(U.S.A)
2 Rupee Coin(India)
1 Rupee Coin(India)
Result
Conclusion
INTRODUCTIONAn alloy is a mixture or metallic solid solution composed of two or more elements.Complete solid solution alloys give single solid phase-microstructure. Alloys usually have different properties from those of the component elements.Alloying a metal is done by combining it with one or more other metals or non-metals that often enhance its properties.Alloys are used in ornaments, bells, statues, buildings, and even coins.
Coins-A Historical Approach
The history of coins extends from ancient times to the present, and is related to economic history, the history of minting technologies, and the history of coin collecting. Coins are still widely used for monetary and other purposes.
Since the time they were invented in 700 B.C., coins have been the most universal embodiment of money. The first coins were made of electrum, a naturally occurring pale yellow mixture of gold and silver that was further alloyed with silver and copper.
Some of the earliest coins were beaten at the edges to imitate the shape of a cow, in indication of their value. Most coins are circular but some were rectangular. Also a lot of coins, especially in China had a hole through the center so they could be tied on to a string.Some of the earliest coins to be made purely from silver and gold were the silver Dirham and gold Dinar.
Coins were first made of scraps of metal. Ancient coins were produced through a process of hitting a hammer positioned over an anvil.The Chinese produced primarily cast coinage, and this spread to South-East Asia and Japan.
The type of mintage method (being hammered, milled or cast) does limit the materials which can be used for the coin. For example antimony coins, (which are very rare) are nearly always cast examples, because of the brittle nature of the metal, and thus it would break if deformed, which is a key part of the milling or hammering process.
Coins today are of great value and are used in our day-to-day lives.
THEORY A coin is a piece of hard material that is standardized in weight, is produced in large quantities in order to facilitate trade, and primarily can be used as a legal tender token for commerce in the designated country, region, or territory.Coins are usually metal or a metallic material and sometimes made of synthetic materials, usually in the shape of a disc, and most often issued by a government. Coins are used as a form of money in transactions of various kinds, from the everyday circulation coins to the storage of large numbers of bullion coins. In the present day, coins and banknotes make up currency, the cash forms of all modern money systems.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.
The coinage metals comprise, at minimum, those metallic chemical elements which have historically been used as components in alloys used to mint coins.
Coins that are intended for circulation have some special requirements based on the conditions they will encounter. For example, a coin may be in circulation for up to 30 years, and so must have excellent wear resistance and anti-corrosion properties. Achieving this goal necessitates the use of base metal alloys. Some metals like manganese have occasionally been used in coins, but suffer from making the coins too hard to take an impression well .
A common base metal alloy for everyday coinage is Cupro-Nickel (also cupronickel), with varying proportions of copper and nickel, most commonly 75% Cu 25% Ni. Cupronickel has a silver color, is hard wearing and has excellent striking properties, essential for the design of the coin to be pressed accurately and quickly during manufacture.
APPARATUS
Test Tubes
Test Tube Holder
Test Tube Stand
Beaker
Burner
Tripod Stand
pH Paper
Wire Gauge
Water Bath
Filter Paper
CHEMICALS REQUIRED
Hydrochloric Acid (HCl)
Sodium Hydroxide
Hydrogen Sulphide Gas
Nitric Acid (HNO3)
Ammonium Acetate
Potassium Iodide
Potassium Chromate
Potassium Ferrocyanide
Ammonium Hydroxide
Ammonium Chloride
Potassium Sulphocyanide
Potassium Nitrite
Ammonium Thiocyanide
Dimethyl Glyoxime
Bromine Water
Ammonium Carbonate
Ammonium Phosphate
Twenty Paise Coin (India)-Made in 2003
Experiment Observation Inference
Zero Group:Add concentrated solution of sodium hydroxide(NaOH) to it.
No white fumes observed. Ammonia(NH4+) is absent.
Group I:Add dilute solution of hydrochloric acid to the original solution.
No white precipitate formed. Pb2+,Ag2+ and Hg22+ are absent.
Group II:Add dilute solution of HCl to the original solution and pass H2S gas through it.
No black or yellow precipitate formed.
Pb2+,Cu2+,As3+ are absent.
Group III:Add NH4Cl and NH4OH(in excess) to the original solution.
A white precipitate is obtained. Al3+ may be present.
Confirmatory For Al3+:
Lake Test:Dissolve the white precipitate obtained int dilute HCl. Add to it two drops of blue litmus solution. To this, add NH4OH drop wise till blue colour develops.
Blue precipitate is observed floating in the colourless solution.
Al3+ is present.
Group IV:Use the same solution as used in Group III tests and pass H2S gas through it.
No precipitate formed. Co2+,Ni2+,Mn2+ and Zn2+ are absent.
Group V:To the original solution, add NH4Cl, NH4OH and (NH4)2CO3.
No white precipitate formed. Ba2+,Ca2+ and Sr2+ are absent.
Group VI:To the original solution, add NH4Cl, NH4OH(in excess) and (NH4)2HPO4.
A white precipitate is obtained. Mg2+ may be present.
RESULT
Twenty Paise Coin of India contains Aluminium(Al3+)and Magnesium(Mg2+).
One Cent Coin(U.S.A)-Made in 1987
Experiment Observation Inference
Zero Group:Add concentrated solution of sodium hydroxide(NaOH) to it.
No white fumes observed. Ammonia(NH4+) is absent.
Group I:Add dilute solution of hydrochloric acid to the original solution.
No white precipitate formed. Pb2+,Ag2+ and Hg22+ are absent.
Group II:Add dilute solution of HCl to the original solution and pass H2S gas through it.
A black precipitate obtained. Cu2+ may be present.
Confirmatory for Cu2+:
Heat the black precipitate with 1-2 ml of 50% HNO3.The precipitate dissolves and add dilute H2SO4 and alcohol.When there is no white precipitate,add NH4OH in excess.
Blue coloured solution obtained. Cu2+ may be present.
Potassium ferrocyanide test:To one part of the blue solution add acetic acid and potassium ferrocyanide solution.
A chocolate brown precipitate is obtained.
Cu2+ is present.
Potassium Iodide test:To another part add acetic acid and potassium iodide solution.
A white precipitate is formed in the brown coloured solution.
Cu2+ is present.
Group III:Add NH4Cl and NH4OH(in excess) to the original solution.
A white precipitate is obtained. Al3+,Cr3+,Fe3+,Fe2+ are absent.
Group IV:Use the same solution as used in Group III tests and pass H2S gas through it.
A dull white precipitate is obtained.
Zn2+ may be present.
Confirmatory for Zn2+:
Sodium hydroxide test:To one part of the original solution add sodium hydroxide solution drop-wise.
A white precipitate is obtained.Add more NaOH to dissolve the precipitate.
Zn2+ is present.
Potassium ferrocyanide test:To another part, add potassium ferrocyanide solution.
A white or bluish white precipitate.
Zn2+ is present.
RESULT
Twenty Paise Coin of India contains Zinc(Zn2+) and Copper(Cu2+).
Two Rupees Coin (India)-Made in 2003
Experiment Observation Inference
Zero Group:Add concentrated solution of sodium hydroxide(NaOH) to it.
No white fumes observed. Ammonia(NH4+) is absent.
Group I:Add dilute solution of hydrochloric acid to the original solution.
No white precipitate formed. Pb2+,Ag2+ and Hg22+ are absent.
Group II:Add dilute solution of HCl to the original solution and pass H2S gas through it.
A black precipitate obtained. Cu2+ may be present.
Confirmatory for Cu2+:
Heat the black precipitate with 1-2 ml of 50% HNO3.The precipitate dissolves and add dilute H2SO4 and alcohol.When there is no white precipitate,add NH4OH in excess.
Blue coloured solution obtained.
Cu2+ may be present.
Potassium ferrocyanide test:To one part of the blue solution add acetic acid and potassium ferrocyanide solution.
A chocolate brown precipitate is obtained.
Cu2+ is present.
Potassium Iodide test:To another part add acetic acid and potassium iodide solution.
A white precipitate is formed in the brown coloured solution.
Cu2+ is present.
Group III:Add NH4Cl and NH4OH(in excess) to the original solution.
A white precipitate is obtained. Al3+,Cr3+,Fe3+,Fe2+ are absent.
Group IV:Use the same solution as used in Group III tests and pass H2S gas through it.
A black precipitate is obtained. Ni2+ may be present.(If the original solution is green).
Confirmatory for Ni2+:
Dimethyl glyoxime test:To one part of the original solution add ammonium hydroxide solution and few drops of dimethyl glyoxime.
A bright rose red precipitate is obtained.
Ni2+ is present.
Sodium hydroxide - bromine water test:To another part add sodium hydroxide (in excess) and bromine water and boil.
A black precipitate is obtained. Ni2+ is present.
RESULT
Two Rupee Coin of India contains Copper(Cu2+) and Nickel(Ni2+).
One Rupee Coin (India)-Made in 2010
Experiment Observation Inference
Zero Group:Add concentrated solution of sodium hydroxide(NaOH) to it.
No white fumes observed. Ammonia(NH4+) is absent.
Group I:Add dilute solution of hydrochloric acid to the original solution.
No white precipitate formed. Pb2+,Ag2+ and Hg22+ are absent.
Group II:Add dilute solution of HCl to the original solution and pass H2S gas through it.
No black or yellow precipitate formed.
Pb2+,Cu2+,As3+ are absent.
Group III:Add NH4Cl and NH4OH(in excess) to the original solution.
A reddish brown precipitate is obtained.
Fe3+ may be present.
Confirmatory for Fe3+:
Dissolve the reddish brown precipitate in dilute HCl, and divide the solution into two parts.
Potassium ferrocyanide test:To one part of the above solution add potassium ferrocyanide solution.
Prussian Blue colouration is obtained.
Fe3+ is present.
Potassium sulphocyanide test:To the second part, add a little potassium sulphocyanide solution.
Blood red colouration is obtained.
Fe3+ is present.
RESULT
Two Rupee Coin of India contains Iron(Fe3+).
RESULT
Amount Country Year Ions presentTwenty Paise Coin India 1938 Al3+ and Mg2+ ions
One Cent Coin U.S.A 1987 Cu2+ and Zn2+ ions
Two Rupee Coin India 2003 Cu2+ and Ni2+ ions
One Rupee coin India 2010 Fe3+ ion
BIBLIOGRAPHY LABORATORY MANUAL OF CHEMISTRY
BY- VEENA SURI
DINESH COMPANION CHEMISTRY
BY- S.K. MALHOTRA
WEBSITES —
http://www.wikipedia.com
http://www.cbseprotal.com