tentukan nomor atom relatif atom L. mohon bantuannya

pH L(OH)3 = 10 + log 6
pOH = 4 - log 6 ==> [OH-] = 6x10^-4
Kb L(OH)3 = [OH]^2/M
= (6x10^-4)^2/0,03 = 1,2x10^-5
Garam hidroliais LCl3 bersifat asam.
pH = 5 ==> [H+] = 10^-5
[H+] = √(Kw/Kb) [LCl3]
10^-5 = √(10^-14/1,2x10^-5) [LCl3]
[LCl3] = 0,12 molar
0,12 = 9,75/Mr x 1000/500
Mr LCl3 = 162,5 g/mol
162,5 = Ar L + 3(35,5)
Ar L = 56 g/mol