Separate mixture of ortho and para Nitro-aniline by Column Chromatography.

 Separate mixture of ortho and para Nitro-aniline by Column Chromatography.

Theory: 

Ortho and Para Nitro aniline can be separated by column chromatography using Alumina as adsorbent and benzene as solvent.

Requirements:

Chromatographic tube, sample Adsorbent (Al₂O₃), Benzene (solvent), Ortho and Para Nitro aniline for separation.

Procedure:

• Prepare a slurry of alumina in benzene. 
• Place a small glass wool stopper at the bottom of the column tube and about 10 ml of benzene solvent. 
• Pour the slurry into the column tube to obtain a column of about 20 in length and cover the packaging with filter paper or a plastic plate to prevent column disruption when the solvent is added.
• Weigh about 0.25 grams each of ortho nitro aniline and para nitro aniline and dissolve the mixture in about 30 ml of benzene. 
• Let the solvent in the column tube flow by opening the tap at the bottom end of the column tube. 
• When the column surface is about to dry, add the mixed solution quickly to the column. Immediately attach the tape funnel using a rubber tube to the top end of the tube and fill it with gasoline. 
• When the solution has fallen almost from the top of the column allowing the benzene to flow into the column, the aniline nitro will start to separate into two yellow bands which will start moving downwards. 
• Continue elution and collect both restrictions into separate containers. Concentrate both solutions and collect the formed crystals. 
• Identify the two compounds and record the results.

Result:

1. Orthonitro aniline

• Colour = Yellow
• Yield=....... g 

2. Para Nitro aniline

• Colour = Yellow 
• Yield ........g

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