Question

Larutan NH4OH 0.1 M mempunyai PH=11 di encerkan 100 kali, maka PH larutan hasil pengenceran adalah

Answer 1

PH = 11
POH = 3
OH⁻ = 10⁻³
[OH⁻]= √kb x M
10⁻³ = √kb x 10⁻¹
------------------------- kuadratkan kedua ruas
10⁻⁶ = kb x 10⁻¹
kb = 10⁻⁵

M1 V1 = M2 V1
10⁻¹ V1 = M2 100V1
M2 = (10⁻¹ V1) / 100 V1
M2 = 10⁻³

OH⁻ = √Kb x M
OH⁻= √10⁻⁵ x 10⁻³
OH⁻ = √10⁻⁸
OH- = 10⁻⁴
POH = 4
PH = 14-4
PH = 10