Question

The pKa of benzoic acid is 4.2. At pH 2.0, it will exist mainly as and occupy the layer. At pH 4.2, it will exist mainly as and occupy the:_______________

Answer 1

Answer:

pH 2.0; benzoic acid, layer: organic

pH 4.2; benzoic acid and benzoate anion, water layer

Explanation:

pH2.0: a lower PH than the pKa it becomes protonated and remains in the organic layer as benzoic acid, organic layer:

pH 4.2: at pH of 4.2 moves to the benzoic acid and benzoate anion, layer: water and organic

pH 12.0: at pH above the pKa it is more soluble in water hence benzoate anion, layer: water