Question

3) Draw the products of each reaction shown below. Circle which side of the equilibrium (left or right) is favored based on your knowledge of Kos. and boo * 9. roho 4) The phenols shown below have approximate pka values of 4, 7, 9, 10, and 11. Which pk, value belongs to which phenol?

Answer 1

3)

In an acid - base reactions, the equilibrium always favor the reaction side with weak acid and bases because both weak acid and bases are of lower energy than that of strong acid and bases. So the given reaction equilibrium favors the marked side (presence of weak acid and base)

+ OH ༧ རྣམས་ ༡ བྱ ས ་ རྒྱ ལ ༌ པ ་ ， + OE NH Na +

4)

In molecules 1,2 and 5, presence of electron withdrawing group makes them more acidic (low pKa) among these molecule -1 (2,4-Dinitrophenol) having 2 nitro group makes them more acidic. Then comes molecule - 2 (p-Nitrophenol) and last molecule - 5 (3-Chlorophenol).

In molecules 3 and 4, molecule - 4 (Phenol) do not posses any other electron releasing or withdrawing group. but in case of molecule -4 (2,3,5-Trimethylphenol) there is 3 methyl group which is strong electron donating group. So, the basicity increases (high pKa)

The ascending order of pKa of the molecules is given below

Appronimate pka OH M