Q. In order of proton accepting tendency will be

 3161  196 AIPMTAIPMT 2001Equilibrium Report Error

Solution:

Basic strength << rate of accepting a proton.
In has lone pair of electron which intensity due to electrons releasing R-group and increase the tendency to donate lone pair of electrons to H+. Secondly as the size of the ion increases, there is less attraction for H+ and form weaker bond with H-atom and less basic. The order of the given series is