Jawaban:

9

Penjelasan:

Hitung Nol Asam Lemah dan Basa Kuat terlebih dahulu.

Mol CH3COOH = M x V

= 0,2 M x 100 ml

= 20 mmol

Mol NaOH = M x V

= 0,2 M x 100 ml

= 20 mmol

Persamaan Reaksi :

CH3COOH + NaOH ---> CH3COONa + H2O

20 mmol 20 -

20 mmol 20 20 mmol

- - 20 mmol

asam lemah dan basa kuat habis bereaksi, garam CH3COONa bersifat basa.

Molaritas garam

= mol /Volume total

= 20 mmol/200 ml

= 0,1 M

asumsi Ka = 10^(-5)

[OH-] = akar Kw x M garam/Ka

= akar 10^(-14) x 0,1 M / 10^(-5)

= akar 10^(-10)

= 10^(-5) M

pOH = -log [OH-] = -log 10^(-5) = 5

pH = 14 - 5 = 9