Respuesta :

Answer:

pH= 9.2

Explanation:

Henderson hasselbach equation

pKa= log Ka= log (4.9 x 10^-10)=9.3

[tex]pH=Pka+log \frac{[A-]}{[HA]}[/tex]

[tex]pH=9.3+log \frac{[CN-]}{[HCN]}[/tex]

[tex]pH=9.3+log \frac{[0.64 M]}{[0.83 M]}[/tex]

pH= 9.2