Question

The degree of ionization of a 0.1M bromoacetic acid solution is 0.132. Calculate the pH of the solution and the `pK_(a)` of bromoacetic acid.

Answer 1

Correct Answer - `pH = 1.88, pK_(a) = 2.70`
Degree of ionization, `alpha` = 0.132
Concentration, `c = 0.1 M`
Thus, the concentration of `H_(3)O+ = c.alpha`
`= 0.1 xx 0.132`
`= 0.0132`
`pH = -"log"[H^(+)] `
`= -log (0.0132)`
`= 1.879 : 1.88`
Now,
`K_(a) = Calpha^(2)`
`= 0.1 xx (0.132)^(2)`
`K_(a) = .0017`
`pK_(a) = 2.75`