Ionisation constant of a weak base MOH is given by the expression
Values of ionization constant of some weak bases at a particular temperature are given below:
Base | Dimethylamine | Urea | Pyridine | Ammonia |
Arrange the bases in decreasing order of the extent of their ionization at equilibrium. Which of the above base is the strongest?
As per the information available from the question, pKb values for Di-methylamine, ammonia, pyridine and urea are respectively 3.29, 4.752, 8.752, and 13.8861.
We know that, Higher is the value of Kb stronger will be the base. When we arrange then in decreasing order of extent of their ionization at equilibrium, they can be written as,
So, the answer is Dimethylamine > Ammonia > Pyridine > Urea