CHRIST NAGAR SENIOR SECONDARY

SCHOOL

CHEMISTRY PROJECT

TOPIC:

ORGANIC PREPARATION

SUBMITTED BY

DEEPAK G S

XII A

REG NO

CERTIFICATE

This is to certify that this project entitled “ORGANIC PREPARATION”, is bonafide record of the work done by DEEPAK G S, Register No:……………..

For the requirement of the Plus Two Practical examination, conducted by Central Board Of Secondary Education (AISSCE) , during the academic year 2015-2016

Internal Examiner External Examiner

Head of the Institution

ACKNOWLEDGEMENT

During the course of this project work,I faced a lot of hardships that was erased only with the help of our teachers and almighty .

On this occasion , I would like to thank each and every one who has aided the progression of this work.

I express my sincere gratitude to our principal Rev.Fr.Mathew Arekalam for his constant encouragement throughout the duration of the project.

In particular, I thank Ms. Asha Rani and Ms. Jalaja priya ,our Chemistry teacher for guiding us to the successful completion of this project .

I also thank Mr Prasanth our Chemistry lab assistant for giving us the help and support doing our project work.

Last, but certainly not the least I thank almighty for giving me the presence of mind and confidence which finally led to the realisation of this project

ORGANIC

SYNTHESIS

CONTENTS

THEORY

APPARATUS

CHEMICALS

RESULT

PRECAUTIONS

EXPERIMENT

AIM: TO PREPARE 2-NAPHTHOL ANILINE DYE

THEORY

2-Naphthol aniline dye or Benzeneazo-2-naphthol is a scarlet dye. It belongs to a large class of Azo-compounds, all of which contain the characteristics grouping

C –N=N-C

Azo compounds are all coloured compounds. For the preparation of the dye , aniline is diazotized and the diazonium salts obtained is subjected to coupling reaction with 2-Naphthol

APPARATUSOne 100mL conical flask, one 100mL beaker, one 250mL beaker, ice bath, glass rod, Buchner funnel, water pump.

CHEMICALS

Aniline

Sodium nitrite

2-Naphthol

Conc. Hydrochloric acid

Glacial acetic acid

PROCEDURE

1. Take a 100mL conical flask and add 4.5mL of aniline, 10mL of conc. HCl and 20mL of water. Cool this solution to 5⁰C by placing the conical flask in a trough containing ice cold water.

2. In a 100mL beaker dissolve 4g of Sodium nitrite in 20mL of water and cool this solution also to 5⁰C.

3. Now slowly add sodium nitrite solution to the solution of aniline in conc.HCl.

4. Dissolve 7g of 2-Naphthol in 60mL of 10%NaOH solution taken in a 250mL beaker and cool this solution to 5⁰C by placing in an ice bath. Some crushed ice may be added directly to facilitate cooling.

5. Now add the diazotized solution very slowly to the Naphthol solution with constant stirring. The mixed solutions immediately develop a deep red colour and the Benzene azonaphthol rapidly separates as red crystals.

6. When the addition of diazo solution is complete, allow the mixture to stand in ice-salt mixture for 30 minutes, with occasional stirring. Filter the solution through a Buchner funnel under suction from the pump. Wash the Benzeneazo-2-naphthol with water and dry the crystals obtained by pressing between the folds of filter paper.

7. Recrystallize the product from glacial acetic acid. Filter the crystals obtained at the pump. Wash with a few mL of ethanol to remove acetic acid Benzeneazo-2-naphthol is obtained as deep red crystals. Expected yield is 3g and melting point is 133⁰C.

RESULT

3g of Benzenoazo-2-naphthol is obtained as deep red crystals with melting point 133⁰C.

PRECAUTIONS1. The solution of the aniline hydrochloride should be

cooled to 5⁰C and this temperature maintained throughout the addition of the sodium nitrite solution.

2. Addition of sodium nitrite should be very slow because the reaction is exothermic and may cause the temperature to rise.

3. Always add Diazonium chloride solution to β-Naphthol solution for formation and not vice-versa.