Answer : The pH of calcium acetate solution will be 9.38.
Explanation : When calcium acetate dissocates completely in solution to form Calcium(+2) ions and two acetate ions, this gives the acetate ion concentration as
(2 X 0.51 M) = 1.02 M
Acetate ion then hydrolyzes as follows;
[tex] C_{2}H_{3}O_{2}^{-} + HOH <----> HC_{2}H_{2}O_{2} + OH^{-} [/tex]:
Now, Kb will be = [tex] [HC_{2}H_{2}O_{2}] [OH^{-}][/tex] / [tex][C_{2}H_{3}O_{2}^{-}] [/tex]
= Kw / Ka
= 1 x [tex] 10^{-14} [/tex] / 1.8 x [tex]10^{-5}[/tex] = 5.6 × [tex]10^{-10}[/tex]
[tex] [OH^{-}] [/tex] = 2.4 × [tex]10^{-5}[/tex]
Now, we know , pOH = -log [tex] [OH^{-}] [/tex] = 4.62
So, the pH = 14 - pOH = 14 - 4.62 = 9.38
