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In the experiment of extraction, what is the organic layer? and in a separatory funnel, will this organic layer be on top or below the aqueous layer?

In the experiment of extraction, what is the organic layer? and in a separatory funnel, will this organic layer be on top or below the aqueous layer?

Macroscale and Microscale Organic Experiments
Macroscale and Microscale Organic Experiments
7th Edition
ISBN:9781305577190
Author:Kenneth L. Williamson, Katherine M. Masters
Publisher:Kenneth L. Williamson, Katherine M. Masters
Chapter4: Recrystallization
Section: Chapter Questions
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In the experiment of extraction, what is the organic layer? and in a separatory funnel, will this organic layer be on top or below the aqueous layer? (Kindly view the attached methodology to know the materials being used and to know what's happening).

Experimental Procedure: Obtain a sample vial containing naphthalene and benzoic acid. Grind the mixture thoroughly in a mortar and determine its m.p. Dissolve the mixture in 20 mL ethyl acetate and place it in a separatory funnel. Extract the organic layer with 10 mL cold 10% NaOH solution. Shake carefully with frequent release of pressure into the fume hood (Why does pressure build up?), then allow the separatory funnel to stand uncapped until the emulsion breaks and a clear separation of layers is observed. In a 100 mL beaker, collect and retain the aqueous (bottom) layer, which contains the sodium salt of benzoic acid. Then extract the organic layer once again with a further 10 mL cold 10% NaOH solution. Collect and retain the aqueous layer in the same 100 mL beaker used for the first fraction. Transfer the organic layer into a dry 50 mL beaker by pouring it from the top of the separatory funnel (Why should you not drain the organic (upper) layer through the tip of the separatory funnel?). To recover the benzoic acid, carefully add about 10 mL concentrated HCI DROPWISE to the aqueous layer until no further benzoic acid precipitates. Filter by suction using a Buchner funnel to collect the benzoic acid and wash it with two 5 mL portions of ice-cold water (What is the purpose of washing and why is ice-cold water used?). Allow the benzoic acid to dry in the Buchner funnel and then record its m.p. and mass. The ethyl acetate layer should contain only naphthalene, which can be recovered as follows. First, add approximately 1.0 g anhydrous sodium sulfate to remove any water from the ethyl acetate and allow the mixture to stand for 5 min. To remove the sodium sulfate, filter the mixture by gravity into a pre-weighed evaporating dish containing a boiling chip. Ensure the tip of the stem of the funnel is below the rim of the evaporating dish to avoid splashing and loss of product. Rinse the beaker with 3 mL ethyl acetate and pour it into the evaporating dish through the filter paper (What is the purpose of this step?). Remove the ethyl acetate from the naphthalene by evaporation on the steam bath in the common fume hood (What is the boiling point of ethyl acetate?). Allow the evaporating dish to cool down and the naphthalene to solidify. Wipe the outside of the evaporating dish to remove any water before weighing it to determine yield of your dried product. In the fume hood, gently scrape the naphthalene in the evaporating dish to collect it. Measure the melting point.
Transcribed Image Text:Experimental Procedure: Obtain a sample vial containing naphthalene and benzoic acid. Grind the mixture thoroughly in a mortar and determine its m.p. Dissolve the mixture in 20 mL ethyl acetate and place it in a separatory funnel. Extract the organic layer with 10 mL cold 10% NaOH solution. Shake carefully with frequent release of pressure into the fume hood (Why does pressure build up?), then allow the separatory funnel to stand uncapped until the emulsion breaks and a clear separation of layers is observed. In a 100 mL beaker, collect and retain the aqueous (bottom) layer, which contains the sodium salt of benzoic acid. Then extract the organic layer once again with a further 10 mL cold 10% NaOH solution. Collect and retain the aqueous layer in the same 100 mL beaker used for the first fraction. Transfer the organic layer into a dry 50 mL beaker by pouring it from the top of the separatory funnel (Why should you not drain the organic (upper) layer through the tip of the separatory funnel?). To recover the benzoic acid, carefully add about 10 mL concentrated HCI DROPWISE to the aqueous layer until no further benzoic acid precipitates. Filter by suction using a Buchner funnel to collect the benzoic acid and wash it with two 5 mL portions of ice-cold water (What is the purpose of washing and why is ice-cold water used?). Allow the benzoic acid to dry in the Buchner funnel and then record its m.p. and mass. The ethyl acetate layer should contain only naphthalene, which can be recovered as follows. First, add approximately 1.0 g anhydrous sodium sulfate to remove any water from the ethyl acetate and allow the mixture to stand for 5 min. To remove the sodium sulfate, filter the mixture by gravity into a pre-weighed evaporating dish containing a boiling chip. Ensure the tip of the stem of the funnel is below the rim of the evaporating dish to avoid splashing and loss of product. Rinse the beaker with 3 mL ethyl acetate and pour it into the evaporating dish through the filter paper (What is the purpose of this step?). Remove the ethyl acetate from the naphthalene by evaporation on the steam bath in the common fume hood (What is the boiling point of ethyl acetate?). Allow the evaporating dish to cool down and the naphthalene to solidify. Wipe the outside of the evaporating dish to remove any water before weighing it to determine yield of your dried product. In the fume hood, gently scrape the naphthalene in the evaporating dish to collect it. Measure the melting point.
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