Question

Tolong kerjakan nomee 1 dan 2, dengan cara

Memenuhi ketentuan dapet jawaban terbaik

Answer 1

Verified answer

PH masing-masing larutan sebelum bercampur

CH3COOH 0,1 M (Ka = 10–5)

CH3COOH ⇔ H+ + CH3COO–

[H+ ] = \sqrt{Ka x M}

[H+ ] = \sqrt{ 10^{-6} }

[H+ ] = 10^{-3} M

pH = - log [H+ ]

= - log 10-3

= 3



NaOH 0,1 M

NaOH → Na+ + OH–

[OH- ] = x · [OH]

= 1 · 0,1

= 0,1 M

pOH = - log [OH- ]

= - log 0,1

= - log 10-1

= 1

pH = 14 – pOH

= 14 – 1

= 13



pH setelah pencampuran

Reaksi CH3COOH + NaOH → CH3COONa + H2O

Mol mula-mula 20 mmol 10 mmol

Mol reaksi 10 mmol 10 mmol 10 mmol 10 mmol

-------------------------------------------------------------------------------------------------

Mol sisa 10 mmol - 10 mmol 10 mmol

(dalam 200 ml larutan)

[CH3COONa] = \frac{mol CH3COONa}{volume} \\ =\frac{10}{200}

= 0,05M

[CH3COOH] = \frac{(mol CH3COOH)}{volume} \\ =\frac{10}{200}

= 0,05M

H+ = Ka. \frac{CH3COOH}{CH3COONa}

H+ = 10-5 \frac{0,05}{0,05}

H+ = 10^{-5}

pH = -log [H+]

= -log 10-5

= 5

Jadi, pH setelah pencampuran adalah 5