Chem 361 lab 3 - Preparation of Phenyl Azo Beta Naphthol PDF

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Summary

Preparation of Phenyl Azo Beta Naphthol...

Description

Daood Tanvir Gill (20-11214) Experiment # 3 Preparation of Phenyl-Azo-β-Naphthol

Reagents

Equipment     

Beakers Pipette Pipette Sucker Filter Paper Funnel

    

Concentrated HCl Aniline Sodium nitrite Beta-naphthol 20% NaOH

Procedure 1. Take three 100 ml beakers and prepare the following solutions in each.

Beaker 1

Beaker 2

Beaker 3

2. 

3 mL distilled water



Add 2 mL concentrated HCl



Place in ice bath



Add 1 mL of aniline



2 mL of water



2g of β-naphthol



Dissolve 1.2 g of NaNO2



8 mL of 20% NaOH solution

Add the contents of Beaker 2 to Beaker 1 while it is placed in the ice bath. 3. After 10 minutes, pour the contents of Beaker 1 into Beaker 3 while continuously stirring, immediate red precipitation is seen. 4. Filter the product. Dry and weigh. 5. Calculate % yield.

Chemical Reaction Chem 361 Lab Report

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Daood Tanvir Gill (20-11214)

Mechanism

Calculation Chem 361 Lab Report

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Daood Tanvir Gill (20-11214) In this equation Aniline is the limiting reagent we will find the theoretical yield using Aniline. Aniline

:

1

:

Mole ratio Molar Mass

93.13 g/mol

Given Mass of Aniline

9g

Phenyl-Azo-β-naphthol

: :

1 248.285 g/mol xg

Theoretical Mass = (9 g x 248.285 g/mol) / (93.13 g/mol) = 24.03 g

Percentage Yeild Obtained Mass of Phenyl-Azo-β-naphthol = 11.57 g % Yeild = (Actual / Thereotical) x 100 = (11.57 / 24.03) x 100 =

48.15 %

Applications  

a diazo-conjugate dye, used as an industrial dye to color hydrocarbon solvents, oils, fats, waxes, shoes, and floor polishes used for staining in histology which stains lipid structures

Chem 361 Lab Report

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Daood Tanvir Gill (20-11214) Precautions 1. The solution of the aniline hydrochloride should be cooled to 5°C, and this temperature should be 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 dye formation and not vice-versa. 4. Wear a lab coat 5. Wear face mask as there might be toxic or irritating fumes around 6. Wear gloves chemicals might be corrosive as they cause harm to our skin.

Chem 361 Lab Report

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