We are asked to determine the pKb of the butyrate ion given the pKa of butyric acid.
Butyric acid is a weak acid (i.e. does not completely dissociate in solution).
The dissociation in water is:
C4H8O2(aq) + H2O(l)→C4H7O2-(aq) + H3O+(aq) pKa = 4.84.
Butyric acid is responsible for the foul smell of rancid butter. The pKa of butyric acid is 4.84.
Calculate the pKb for the butyrate ion.