Question

A. Draw a seperatory funnel with isopropyl acetate and aqueous solution in it. Label the layers. Which is the top and which is the bottom and why is this so? What property of each liquid determines if it will be the top or the bottom layer.

B. What properties of the compounds is this separation based on? Which of the two (Benzoic acid and ethyl-4-hydroxybenzoate) is more acidic?

C. Which of the two compounds is extracted into the aqueous layer with sodium bicarbonate extraction? Why is this so?

Answer 1

Top layer is organic layer that is isopropylacetate and bottom layer is aqueous solution. Because the solution which has more density is at bottom and the liquid which has less density is at top. Isopropyl acetate has lower density than aqueous solution so it is present at top.

Density of each liquid determines if it will be the top or the bottom layer.

B) Based on polarity of the compounds they can be separated by solvent extraction. Polar compound dissolves in polar solvent and non-polar compound dissolves in non-polar solvent.

Benzoic acid is more acidic as it has carboxylic acid as functional group. ethyl-4-hydroxybenzoate is less acidic because it has ester functional group and phenolic functional group. Phenol is less acidic than carboxylic acid. Hence benzoic acid is more acidic.

C) Benzoic acid is extracted into the aqueous layer with sodium bicarbonate extraction. Because benzoic acid is more acidic and it can dissociate bicarbonate into carbon dioxide and water. Phenol is less acidic and it can't dissociate bicarbonate so it remains in organic layer.