Investigatory Chemistry Project

7/21/2019 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


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


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


No change Group IVabsent


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


A colourless,odourlessgas is

evolved

CO32-

detected


MgSO4 solution

A white ppt.

is obtained

CO32-

confirmed

3. To the sample addconc. H2SO4

A colourlesspungent gasis given off

Cl-

detected


dilute HNO3, Boil,cool and add AgNO3

A white ppt.

is obtained

Cl-

confirmed


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CATION



NaOH and heat

No change Group 0

absent6. To the sample add

dilute HClNo change Group I

absent




NH4OH and NH4Cl

A white ppt. is

obtained

Al3+

detected

9. Dissolved the ppt.in dilute HCl. Addblue litmus. Now

add NH4OH

A blue ppt. isobtained

Al3+

confirmed

10. To the above test

tube add H2S

No change Group IV

absent

11. To the sample addNH4OH and NH4Cl

and Solid(NH4)2CO3

A white ppt. isobtained

Group Vabsent

12. Dissolve the ppt. in

CH3COOH anddivide it into 3parts

(i) To the first part

add K2CrO4 solution

No change Ba2+ absent

(ii) To the second partadd (NH4)2C2O4


Ca2+ present

13. To the sample addNH4OH and NH4Clin excess. Add(NH4)2HPO4


Mg2+

detected


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Close-UP

ANION



A colourlesspungent gasevolves which

turns acidifiedpotassiumdichromate

paper green

SO32-

detected


BaCl2solution

A white ppt. is

obtained

SO32-

confirmed


concentrated

H2SO4

No change Conc. H2SO4

group

absent

4.(i)

(ii)

To the sample add

CH3COOH and

CaCl2

Add dilute HCl

A white ppt. is

obtained

The ppt.

dissolves

F- present


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CATION


5 To the sample add

NaOH and heat

No change Group 0

absent6. To the sample add

dilute HClNo change Group I

absent




NH4OH and NH4Cl

A brown ppt.

is observed

Fe3+

detected

9. Dissolve the ppt. indilute HCl and addPotassium

Ferrocyanide

A prussianblue colour isobtained

Fe3+

confirmed

10. To the above test

tube add H2S

No change Group IV

absent

11. To the sample addNH4OH, NH4Cl and

Solid (NH4)2CO3


Group Vpresent

12. Dissolve CH3COOHand divide into

three parts

(i) To the first partadd K2CrO4solution

No change Ba2+absent

(ii) To the second part

add (NH4)2SO4solution

No change Sr2+absent

(iii) To the third part

add (NH4)2C2O4 andNH4OH

A white ppt. is

obtained

Ca2+

present

13. To the sample addNH4OH and NH4Cl inexcess and add(NH

4)2PO

4

No change Mg2+ absent


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COMPARITIVE INFERENCE

TABLENAME OF THE

TOOTHPASTE

F- Ca2+ CO32- SO3

2- Cl- SO42- Al3+ Fe3+ Mg2+

COLGATE

PEPSODENT

CLOSE-UP


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CONCLUSIONS

For the ideal toothpaste, sodium, calcium, Magnesium,chloride and sulphate should be present.

On the basis of comparative inference table _________

is the best of all toothpaste as it contains most of the

essential constituents of toothpaste.


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Precautions

1.

Handle chemicals carefully.2. Use test tube holder to hold the test tube.

3. Never add water to conc. Acids

4. Never touch any chemical with hands directly.

5. Use a dropper for concentrated Acids.

Investigatory Chemistry Project

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