The dissociation of (C2H5 )3 N takes place as follows:
(C2H5 )3 N --> (C2H5)2N- + C2H5 +
0.2 – x x x
Whereas, dissociation of ethanol is follows:
C2H5 OH --> C2H5 + + OH-
Thus, the concentration of C2H5 + is equivalent to OH-
Kb = [(C2H5)2N- ] [C2H5 + ] / [(C2H5 )3 N ]
5.2 * 10-4 = x^2 / 0.2
x = [OH- ] = 5.01 * 10^-2 M
The concentration of hydroxyl ion is 5.01 * 10^-2 M
P (OH) = - log [OH- ]
= - log [5.01 * 10^-2 ]
= 1.31
The Poh is 1.31
