To answer this question we have to find the value of ka, to do it, we can use the value of kb. The product of the kb of a base and the ka of its conjugated base is kw(1x10^-14):
[tex]\begin{gathered} k_a\cdot k_b=k_w \\ k_a=\frac{k_w}{k_b} \\ k_a=\frac{1\times10^{-14}}{4.38\times10^{-5}} \\ k_a=2.88\times10^{-10} \end{gathered}[/tex]
Now, we have to use the equation of Hendersson and Hasselbach:
[tex][/tex]
