Jawaban:

8,7

Penjelasan:

200 ml CH3COOH 0,1 M + 800 ml NaOH 0,025 M

-Hitung Mol Asam dan Basa

Mol CH3COOH = M x V = 0,1 x 200 = 20 mmol

Mol NaOH = 0,025 x 800 = 20 mmol

Persamaan Reaksi:

CH3COOH + NaOH ---> CH3COONa + H2O

20 mmol 20 -

20 mmol 20 mmol 20 mmol

- - 20 mmol

asam lemah dan basa kuat habis bereaksi. garamnya bersifat basa.

M garam

= mol garam / volume total

= 20 mmol / 1000 ml

= 0,02 M

[OH-]

= akar Kw x M garam / Ka

= akar 10^(-14) x 0,02 / 10^(-5)

= akar 0,2 x 10^(-10)

= 0,4 x 10^(-5) M

pOH

= -log [ OH-]

= -log 0,4 x 10^(-5)

= -log 0,4 + 5

= 5,3

pH

= 14 - pOH

= 14 - 5,3

= 8,7