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he crude purification of the reaction product is done using extraction in a sepa

ID: 514839 • Letter: H

Question

he crude purification of the reaction product is done using extraction in a separatory funnel. Explain each extraction step given below: (12 points)

Initial wash with deionized water

What reactants/products are dissolved in the water layer?

What reactants/products are dissolved in the organic layer?

Wash with 5% sodium bicarbonate

What reactants/products are dissolved in the water layer? What reactants/products are dissolved in the organic layer?

Conversion of isopentyl alcohol to isopentyl acetate is an example of a Fisher esterification. Draw the complete mechanism of this reaction using the curved arrow convention, showing all reaction intermediates and products.

Explain how you were able to use infrared spectroscopy to determine whether isopentyl alcohol was converted to isopentyl acetate.

Explanation / Answer

Extraction os reaction mixture in separatory funnel

Initial wash with deionized water :

Excess sulfuric acid used in the reaction would dissolve and gets washed away with water.

The organic product ester and any leftover reactant isopentyl alcohol, acetic acid would dissolve in the organic layer.

Washing with 5% sodium bicarbonate

Acetic acid would react and form sodium salt which would go in water layer.

The reactant isopentyl alcohol If any left and the product ester would be in organic phase.

IR analysis

Isopentyl alcohol would show broad peak for the O-H stretch at around 3350 cm-1 in the IR spectrum. This peak disappears when product ester is formed and a new peak at aroud 1740 cm-1 would appear characterisitic of C=O group.