Question

What is the pH of a solution that contains 0.83M HCN (Ka = 4.9x10-10) and 0.64 M potassium cyanide?

Answer 1

pH= 9.2

Step-by-step explanation:

Henderson hasselbach equation

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

`pH=Pka+log ([A-])/([HA])`

`pH=9.3+log ([CN-])/([HCN])`

`pH=9.3+log ([0.64 M])/([0.83 M])`

pH= 9.2