Chemistry project

CHEMISTRY BOARD PROJECT PREPARATION OF PIGMENTS PRESENT IN POSTER COLOURS

DELHI PUBLIC SCHOOL MATHURA ROAD AKSHAT GUPTA | XII-E | 22/11/16 BOARD ROLL NO:-

INDEX S.NO.

TOPICS

1.

CERTIFICATE

2.

ACKNOWLEDGEMENT

3.

AIM

4.

MATERIAL REQUIRED

5.

ABOUT PAINTS

6.

8.

DESCRIPTION ABOUT DIFFERENT PIGMENTS PREPARATION OF xCHROME YELLOW PREPARATION OF PRUSSIAN BLUE

9.

PREPARATION OF BARIUM WHITE

10.

PREPARATION OF MALACHITE BLUE

11.

OBSERVATION AND RESULT

12.

PRECAUTIONS

7.

CERTIFICATE This is to certify that AKSHAT GUPTA of class XII-E has successfully completed his project on the preparation of pigment present in poster colours under my guidance with which he has also completed the Compulsory project as per the CBSE Curriculum of class XII

Signature of Teacher (Ms. Yusra Faridi)

Signature of Lab Incharge

ACKNOWLEDGEMEN T I express my sincere thanks to my Chemistry teacher Ms. Yusra Faridi with whose encouragement this project has taken shape. HE gave me appropriate advice and guidance which helped in making of this project.

I would like to thank our school’s lab teacher for his cooperation, timely support and help throughout in the making of this project on “The preparation of pigments present in poster colours.”

AIM To prepare the pigments present in the poster colours in laboratory by using various chemicals and reagents

MATERIAL REQUIRED APPARATUS 1.

2.

3.

4.

5.

6.

100ml Beaker Measuring Flask Funnel Filter Paper Glass Rod Dropper

CHEMICAL USED 1.

Blue Vitrol (CuSO4.5H2O) 2.

Sodium Bicarbonate (NaHCO3) 3.

Sodium Sulphate (Na2SO4) 4.

Barium Chloride (BaCl2) 5.

Potassium Chromate (K2CrO4) 6.

Lead Nitrate (Pb(No3)2) 7.

Ferric Chloride (FeCl3) 8.

Potassium Hexacyanoferrate(II) (K4(Fe(CN)6))

ABOUT PIGMENTS

A Pigment is a finally divided material which contributes to optical and other properties of paints. Pigments may be classified according to their composition or source which they are obtained from. However, the most common and useful classification is that coloured pigments can be made using simple chemical reaction and techniques.

Pigments are used for coloring paint ink, plastic, fabric, cosmetics, food and other materials. Most pigments used in manufacturing and the visual arts are dry colorants, usually ground into a fine powder.

This powder is added to a binder, a relatively neutral or colorless material that suspends the pigment and gives the paint its adhesion.

Pigments appear the colors they are because they selectively reflect and absorb certain wavelengths of visible light. White light is a roughly equal mixture of entire spectrum of visible light with a wavelength in a range from about 375 to 400 nm to about 760 or 780 nm. When this light encounters a pigment, parts of the spectrum are absorbed by the chemical bonds of conjugated systems and other components of the pigments.

ABOUT POSTER COLOURS For making poster paints the pigments made by various chemical reactions are thoroughly mixed with the medium. Sometimes the paint hardens but the addition of lukewarm water to it so it can soften up.

CHROME YELLOW Chrome yellow is a Lead(II) Chromate. It occurs naturally as the mineral crocoite but the mineral itself was never used as a pigment in paintings.

In 1797 Lead Chromate has been synthesized in the laboratory and its use as a pigment started in the second decade of the nineteenth century.

Because the pigment tends to oxidize and darken on exposure to air over time and it contains lead, a toxic, heavy metal, it was originally replaced by another pigment, Cadmium Yellow.

PRUSSIAN BLUE Prussian blue is a dark blue pigment. Another name for the colour is Berlin Blue. Prussian Blue was the first modern synthetic pigment. It is employed as a very fine colloidal dispersion, as the compound itself is not soluble in water. It is famously complex, owing to the presence of variable amounts of other ions and the sensitive dependence of its appearance on the size of the

colloidal particles formed when it is made. The pigments is used in paints and it is the traditional BLUE in blueprints.

BARIUM WHITE The majority of synthetic barium sulphate is used a component of white pigments for paints. In oil paint, barium sulphate is almost transparent, and is used as a filter or to modify consistency. One major manufacturer of artist’s oil paint sells “Permanent White” that contains a mixture of titanium white pigment and barium sulphate. The combination of barium sulphate and zinc sulphide is the inorganic pigment called lithopone. In photography it is used as a coating for certain photographic papers.

MALACHITE GREEN It’s a mineral basic copper carbonate, moderately permanent pigment of varying colour. Malachite is perhaps the oldest known green pigment. It is sensitive to acids and to heat. Occurs in Egyptian tomb paintings, in European paintings it seems to have been of importance mainly in the 15th and 16th centuries.

PIGMENTS MADE IN LAB

PERFORMING THE EXPERIMENT

PREPARATION OF CHROME YELLOW Chemically knows as LEAD CHROMATE. 1.

Dissolve 7gm of Potassium Chromate in 50ml water and 10gm Lead Nitrate in 100ml in 2 separate beakers.

2.

Pour the Potassium Chromate solution in the Lead Nitrate and stir continuously.

3.

Lead Chromate separates as precipitate and is the required pigment.

4.

Filter the precipitate and dry the pigment.

Equation involved:K2CrO4 + Pb(NO3)2  PbCrO4 + 2KNO3

PREPARATION OF PRUSSIAN BLUE

Chemically known as COMPLEX FERRO CYANIDE. 1.

Make a solution of 5 gm of Hydrated Iron(III) Chloride in 50ml of water.

2.

Make a solution of 10 gm of Potassium Ferro Cyanide in 75 ml of water.

3.

Add Iron Chloride solution into Potassium Ferro Cyanide solution while stirring briskly.

4.

A dark blue colour very fine powdered type substance precipitates.

5.

Filter the precipitate and wash it with water.It takes along time to filter this substance.

Equation involved:4FeCl3 + 3K4[Fe(CN)6]  Fe4[Fe(CN)6] + 12KCl

PREPARATION OF BARIUM WHITE Chemically known as Barium Sulphate.

1.

Mix 5ml of Sodium Sulphate and 5ml of Barium Chloride solution in a beaker.

2.

Stir and then rest the mixture for 10 minutes.

3.

Filter the white precipitate obtained.

Equation involved:BaCl2 + Na2SO4  BaSO4 + 2NaCl

PREPARATION OF MALACHITE GREEN Chemically known as Aniline Green.

1.

Mix 5ml of Blue Vitrol with 3g of Sodium Bicarbonate.

2.

Stir and rest the mixture for 10 minutes 3.

Filter the precipitate.

Equation involved:CuSO4 + NaHCo3  CO2 + CuCO3 + H20 + Na2SO4

OBSERVATION  For each chemical reaction specific colour precipitate was obtained this forms the pigment that are used in different colours of paints.

RESULT  We have prepared pigments of paint such as Chrome yellow, Prussian blue, Barium white and Malachite green.

PRECAUTIONS  The beaker and the funnel should be washed before.  The amount of reactant to be taken should be measured carefully.  Fresh chemicals should be used.  The funnel must not touch the solution in the beaker.  During the process of setting, the apparatus must not be disturbed.  The chemicals must be handed carefully.

BIBLIOGRAPHY  http://www.jcsparks.com/painted/pig ment  https://en.wikipedia.org/wiki/prussia nblue  https://en.wikipedia.org/wiki/malach itegreen  https://en.wikipedia.org/wiki/barium white

 https://en.wikipedia.org/wiki/chrome yellow