banyaknya CH3COOK (Mr= 98) yang terdapat dalam 100 ml larutan CH3COOK dengan ph = 9,jika diketahui Ka CH3COOH= 10^-5 adalah.....a.0,245 gram b.0,49 gram c.0,98
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hermawansyah76
Pertanyaan
banyaknya CH3COOK (Mr= 98) yang terdapat dalam 100 ml larutan CH3COOK dengan ph = 9,jika diketahui Ka CH3COOH= 10^-5 adalah.....a.0,245 gram b.0,49 gram c.0,98 gr d.9,8 gr e.19,6 gr
2 Jawaban
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1. Jawaban Robinn
pH = 9
pOH = 14 - 9
pOH = 5
[OH-] = 10^-5
[OH-] = √Kw / Ka . M
10^-5 = √10^-14 / 10^-5 . M
10^-10 = 10^-9 . M
M = 10^-10 / 10^-9
M = 10^-1
M = 0,1 M
n = M . V
n = 0,1 . 0,1 L
n = 0,0,1 mol
→ Banyak yg larut :
= n . Mr
= 0,01 . 98
= 0,98 gram -
2. Jawaban Nurulatikajk
CH3COOH + KOH ---> CH3COOK + H2O
pH = 9 , pOH = 14-9 =5 , OH- = 10^-5
OH- = √kw/Ka .[garam]
10^-5 = √10^-14/ 10^-5 .[garam]
10^-10 = 10^-9 .[garam]
[garam] = 10^-10 /10^-9 = 10^-1
n = M . V = 0.1 × 0.1 = 0.01
m = n.Mr = 0.01 × 98 = 0,98 gram