Investigatory Chemistry Project

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    CHEMISTRY

    PROJECT

    S u b m i t t e d b y : - V a n d i t t

    C l a s s : - X I I B

    R o l l n o : - 2 5

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    INDEX

    1.Certificate

    2.Acknowledgement

    3.AIM

    4.Apparatus

    5.Introduction6.Theory

    7.Procedure

    -Colgate

    -Pepsodent

    -Close-UP

    8.COMPARITIVE INFERENCE TABLE

    9.Conclusion

    10.Precautions

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    Certificate

    This is to certify that Vanditt, student of Class XIIth

    B,Navyug School, Sarojni Nagar has completed the

    project having aimTo Detect The Presence Of

    Different Anions And Cations In Different Brands Of

    Toothpasteduring the academic year 2013-14 towards

    partial fulfillment of credit for the chemistry practical

    evaluation of CBSE 2014 and submitted satisfactory

    report as compiled in the following pages under mysupervision.

    Mrs. Taruna Sikri

    Department of Chemistry

    Navyug School, Sarojni Nagar

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    Acknowledgement

    I owe thanks to many people who helped me in thisproject.

    My deep thanks of gratitude are to Mrs. Taruna Sikri,

    our chemistry teacher for helping me in this topic with

    her valuable guidance.

    Finally, I would also thank you my family members and

    friends for their constant support.

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    AIM

    To Detect The Presence OfDifferent Anions And Cations In

    Different Brands Of Toothpaste.

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    Apparatus

    Toothpaste(s):

    Colgate, Pepsodent and Close-UP.

    Chemicals:

    Hydrochloric acid, dilute Sulphuric acid, concentratedSulphuric acid, Barium chloride, Ammonium chloride,

    Ammonium hydroxide, Ammonium carbonate, Acetic

    acid, Nitric acid, Silver nitrate, Calcium chloride,

    Pottasium Ferrocyanide, H2S gas.

    Test tubes, Beakers, Flasks, U-Tubes etc.

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    Introduction

    The invention of toothpaste has brought about arevolution in the field of dentology. Toothpaste and

    tooth powders are the substances used to clean teeth.

    Non cleaning of teeth can cause tooth decay, i.e., hole

    in the enamel or plaque. The dental enamel is the

    hardest material in our body but is formed of calcium

    phosphate and it can be dissolved by acid. The

    presence of specific bacteria metabolize some sugar tolactic acid and low resistance of the enamel to bacteria

    colonization is caused. Prevention of the dental plaque

    protects against the development of caries.

    Toothpaste contain a mildly abrasive substance such

    as calcium carbonate and a detergent or soap, some

    sweetening agent other than sugar and flavouring oilsto make it pleasant to taste and smell. Some

    toothpaste contains fluorides which make the enamel

    surface of the tooth more resistant to bacterial activity

    and act against micro-organisms as a metabolic poison.

    Epidemological study in the US in the 1930s and

    1940s have revealed an inverse relationship between

    the fluoride content of water and rate of dental

    carriers. Generally any standard toothpaste contain

    calcium carbonate, sodium monofluoro phosphate,

    sodium lauryl sulphate, zinc sulphate, alum, some

    flavouring oils are also added.

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    A dentrifices is defined as a cleaning agent in the form

    powder, paste or liquid to be used on the tooth. The

    term does not include devices used in aid in cleaning

    process such as tooth brushes and dental floss. Moderndentrifice are an extension to numerous abrasives and

    cleaning substances used as dentrifices.

    The primary function of a dentrifice is the mechanical

    cleaning of teeth. They prevent the accumulation of

    layers of mucous plaques that gives the appearance of

    yellow teeth. Dentrifices are functionally non antiseptsbut in cleaning teeth they serve as detergents of teeth

    and mucous membranes of the mouth. Dentrifices

    remove accessible products of oral purification. Some

    dentrifices liberate ammonia, which reduce the

    bacterial propagation in the mouth preventing the

    formation of mucous plaques.

    Basic ingredients of a dentrifice are an abrasive and a

    detergent. However, other ingredients of the following

    categories are also added.

    Flavours and sweetness to increase palatability

    Lubricants are also used and emulsifiers or plasticisers

    such as glue.

    Colouring agents are used for aesthetic appeal.

    Mucilage are used to affect homogeneity in case of

    toothpaste to facilitate expulsion from the tube.

    Special substances such as antiseptics and counter

    irritants are also used.

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    Theory

    In qualitative analysis, the given compound is analysedfor the radicals, that is, cations and anions that it

    contains. The common procedure of testing on

    unknown salt is to make its solution and then test this

    solution for the ions present in it. There are separate

    procedure for detecting cation and anion.

    IDENTIFICATION OF ACID RADICAL (ANION)

    The identification of acid radicals is first done on the

    basis of preliminary tests. They can be divided in to

    three categories each with separate group reagent.

    Therefore anion may be identified by performing the

    following tests in order given.

    Dilute H2SO4 test

    Concentrated H2SO4test

    Independent Group (SO42-, PO4

    3-)

    IDENTIFICATION OF BASIC RADICALS (CATION)

    The basic radicals indicated in the preliminary test have

    to be confirmed by applying wet tests, The cations

    have been divided into six groups with suitable group

    reagents. The classification of cations is based on the

    knowledge of solubility products of salts of these basic

    radicals. For adjusting the conditions of precipitation

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    another concept called common ion effect plays and

    important role.

    COMMON ION EFFECT

    Weak acids and weak bases are ionized only to a small

    extent in their aqueous solution. In their solutions,

    unionized molecules are in dynamic equilibrium with

    ions, the degree of dissociation of a weak electrolyte is

    further suppressed if some strong electrolyte which canfurnish some ion common with the ions furnished by

    weak electrolyte is added to solution. This is called

    common ion effect.

    Thus, the suppression of the degree of ionization of a

    weak electrolyte by the addition of some strong

    electrolyte have a common ion, is called common ion

    effect.

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    COLGATE

    ANION

    S.NO. EXPERIMENT OBSERVATION INFERENCE

    1. To the paste adddilute H2SO4

    A colourless,odourless gasis evolved.

    CO32- may be

    present

    2. To the sample addMgSO4 solution.

    A white ppt. isobtained.

    CO32-

    confirmed

    3. To the sample add

    concentrated H2SO4

    No change Conc. H2SO4

    group absent4.(i)

    (ii)

    To the sample addCH3COOH and CaCl2

    Add dilute HCl

    A white ppt. isformed

    The ppt.dissolves

    F- present

    5. To the sample add

    BaCl2 solution

    A white ppt. is

    obtained

    SO42- present

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    CATION

    S.NO. EXPERIMENT OBSERVATION INFERENCE6. To the sample add

    NaOH and heat

    No change Group 0

    absent

    7. To the sample add

    dilute HCl

    No change Group I

    absent

    8. To the above testtube add H2S

    No change Group IIabsent

    9. To the sample addNH4OH and NH4Cl

    No change Group IIIabsent

    10. To the above testtube add H2S

    No change Group IVabsent

    11. To the sample add

    NH4OH, NH4Cl andSolid (NH4)2CO3

    A white ppt.

    is obtained

    Group V

    absent

    12. Dissolve the ppt. in

    CH3COOH anddivide in to 3 parts

    (i) To the first part add

    K2CrO4 solution

    No change Ba2+ absent

    (ii) To the second part

    add (NH4)2SO4

    No change Sr2+ absent

    (iii) To the third partadd (NH4)2C2O4

    A white ppt.is obtained

    Ca2+ present

    13. To the sample addNH4OH and NH4Cl inexcess. Add

    (NH4)2HPO4

    A white ppt.is obtained

    Mg2+detected

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    PEPSODENT

    ANION

    S.NO. EXPERIMENT Observation Inference

    1. To the paste adddilute H2SO4

    A colourless,odourlessgas is

    evolved

    CO32-

    detected

    2. To the sample add

    MgSO4 solution

    A white ppt.

    is obtained

    CO32-

    confirmed

    3. To the sample addconc. H2SO4

    A colourlesspungent gasis given off

    Cl-

    detected

    4. To the sample add

    dilute HNO3, Boil,cool and add AgNO3

    A white ppt.

    is obtained

    Cl-

    confirmed

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    CATION

    S.NO. EXPERIMENT OBSERVATION INFERENCE

    5. To the sample add

    NaOH and heat

    No change Group 0

    absent6. To the sample add

    dilute HClNo change Group I

    absent

    7. To the above testtube ad