Berapakh massa (NH4)2SO4 yang diperlukan untuk membuat 1000ml larutan (NH4)2SO4 dengan ph =5 ? Dik = Mr = (NH4)2SO4 = 132, Kb = NH3 = 10~5

pH = 5
[H+] = 10^-5

(NH4)2SO4 → 2NH4+ + SO4^2-

[H+] = √Kw / Kb . n . M
10^-5 = √10^-14 / 10^-5 . 2 . M
10^-10 = 10^-9 . 2 . M
2 . M = 10^-10 / 10^-9
2 . M = 10^-1
M = 10^-1 / 2
M = 0,05

n = M . V
n = 5 x 10^-2 x 1 liter
n = 5 x 10^-2

m = Mr . n
m = 132 x 0,05
m = 6,6 gram