Contents

Certificate

Acknowledgement

Introduction

Aim of the project

Apparatus

Theory

Procedure

Observation

Result

Bibliography

Certificate

This is to certify that the project entitled

“Dyes” has been submitted by --------- a

student of class XII-F under the Roll

no.__________ for the academic session 2009-

2010. He has completed the project work

Chemistry Department under direct

supervision of the undersigned as per the

requirement for the Board Examination.

(----------)

Department of Chemistry

----------------------

ACKNOWLEDGEME

NTWe want to express our sincere

gratitude to our Chemistry teacher -------------

for her guidance , encouragement and kind

cooperation without which my first ever

chemistry project won’t have been possible.

We are also grateful to Mrs. ---------------,

LABORATORY ASSISTANT, CHEMISTRY

DEPARTMENT for her valuable help during

the preparation of his project.

---------------

XII-F

Roll No.________________

Dyes

Dyes are colored substances which adhere to

the surface of materials and are used to give

color to paper, food stuffs, and various

textiles such as cotton, wool etc.

Chemically a dye contains.

Some groups such as azo, anthraquinone

which is responsible for the color of the

dye.

Some groups such as-COOH, NHSSO3H

which make the dye stick to the fabric by

formation of some salt.

The dye fabrics appear to be colored because

a particular dye absorbs radiation of some

specific wave lengths from the visible region

of electromagnetic radiation that fall on its

surface. The remaining radiations of light are

reflected. For example. If a dye absorbs the

light in the wavelength region.

Corresponding to red, then it would appear

green which is the complementary color or

red.

1) APPARATUS

Funnel, distilled water, filter paper, mortar.

2) CHEMICALS USED

White, sodium carbonate, lead nitrate,

lead chromate.

Light green, copper sulphate, sodium

hydrogen carbonate.

Oxford blue, phthalic anhydride, urea

hydrated copper (II) chloride, ammonium

or sodium molybdate.

Yellow, Potassium chromate, lead nitrate.

WHITE

Dissolve 10g anhydrous sodium carbonate

Na2CO3 in 100 ml water. Cool the solution to

room temperature. To this solution add a

solution of 30g lead nitrate {Pb(NO3)2}

dissolved in 15ml water. The lead to solution

is added slowly with steady stirring. The

formed precipitate of white lead if filtered

using a funnel. The product is washed with

water several times. The cake is spread on

dryness.

Pb(NO3)2+Na2CO3 Pb(NO3)2+2NaNO3

PbCO3+H2O Pb (OH)2+CO2

LIGHT GREEN

To a solution of 5g sodium hydroxide

carbonate (NaHCO3) in 50 ml water is added

with brisk stirring a solution of 15g copper

sulphate in 100 ml water in a beaker.

Evolution of carbon dioxide occurs with the

formation of a pale green precipitate. This

ppt in CuCO3 and is isolated by filtration.

Washing with water and air dried.

CuSO4+NaHCO3 CuCO3+NaHSO4

OXFORD BLUE

A mixture of 6g phthalic anhydride, 8g urea,

and 2g hydrated copper (II) chloride and a

small crystal of ammonium or sodium

molybdate is powdered in a mortar. Take it in

a test tube and heat very gently. The mixture

melts to a green liquid gas is evolved and it

turns dark green and then blue. It solidifies

partly at this stage the heating it continued

until the fine blue solid first obtained changes

to a brownish green solid. The reaction

product is cooled and powered in a mortar.

This is crude pigment. This is difficult to

filter. A wet mass is obtained on filter paper.

It is dried in warm air.

3K4{Fe(CN)6}+4FeCl3 Fe4{Fe(CN)6l3+12

KCL

YELLOW

(Lead chromate or chrome yellow)

Dissolve 7 g of potassium chromate (K2CrO4)

in 5ml water and 10g Pb(NO3)2 100ml water

in two separate beakers. In case heating or

warming is necessary to effect complete

dissolution both the solution are separately

cooled to room temperature. Pour the

chromate solution with stirring into the lead

nitrate solution. The required pigment, lead

chromate separates as yellow precipitate. It

is filtered, washed with water and air dried.

K2CrO4+Pb(NO3)2 PbCrO4+2KNO3

RESULT

Now that dyes/paints have been made, they

can be used as oil bases on pastel sheets. The

prepared colors include white, yellow, blue

and green.

1.Pradeep Fundamental Chemistry

2.Laboratory Manual in Chemistry- Together

with Chemistry