Question

Tolong yang bisa bantu jawab pertanyaan ini jawab yaa, besok dikumpul. kalo bisa sama jalannya jg, thanks ya frd.

Answer 1

1.
pH=10
pOH=4
[OH-] = 10^-4

Mg(OH)2 => Mg2+ + 2OH-

Perbandingan molaritas= perbandingan kelarutan = perbandingan koefisien
Jika kelarutan OH- = 10^-4
Maka kelarutan Mg2+= 1/2(10^-4) = 5.10^-5

Ksp= [Mg2+] [2OH-]^2
Ksp= 5.10^-5 [10^-4]^2
Ksp= 5.10^-13 (E)

2.
L(OH)2 => L2+ + 2OH-

Jika kelarutan L(OH)2 = 5.10^-4
Maka kelarutan 2OH- = 2.5.10^-4 = 10^-3

pOH= -log [OH-]
pOH= -log 10^-3
pOH=3
pH=11 (D)

3.

CaF2 => Ca2+ + 2F-

Ksp= [Ca2+][2F-]^2
3,3.10^-11 = S . (2s)^2
33.10^-12 = 4S^3
8,25 . 10^-12 = s^3
S= 2,02 . 10^-4

2,02 . 10^-4 = n / 0,2
4,04 . 10^-5 = n

Massa= 4,04 . 10^-5 . 78= 315,12 . 10^-5
= 3,1512 .10^-3 gram = 3,1512 mg (C)

4.

LSO4 => L2+ + SO4 2-

Ksp= [L2+][SO4 2-]
2,5.10^-5 = S . S
25.10^-6 = S^2
S= 5.10^-3

5.10^-3 = n / 0,5
n= 25 . 10^-4

0,34 = 25. 10^-4 . Mr
Mr= 136 (C)

5.
CaCl2 => Ca2+ + 2Cl-

Jika CaCl2 = 0,01M maka Ca2+ = 0,01M

CaF2 => Ca2+ + 2F-

Ksp= [Ca2+][2F-]^2

Masukin Ca2+ dari CaCl2

4.10^-11 = 0,01 (2S)^2
4.10^-9 = 4S^2
S= 1. 10^-4,5 (C)

6.
1,74 . 10^-2 = n . 58
n= 3.10^-4

M= 3.10^-4 / 0,1
M= 3.10^-3

Mg(OH)2 => Mg2+ + 2OH-

Jika kelarutan Mg(OH)2 = 3.10^-3
Maka kelarutan Mg2+ = 3.10^-3
Maka kelarutan OH-= 6.10^-3

Ksp= [Mg2+][2OH-]^2
Ksp = 3.10^-3 . 36.10^-6
Ksp= 108.10^-9= 1,08.10^-7 (E)

7.
Ag2S => 2Ag+ + S2-

Jika kelarutan Ag2S = a
Maka kelarutan Ag+ = 2a
Maka kelarutan S2- = a

Ksp= [2Ag+]^2 [S2-]
Ksp= (2a)^2 . a
Ksp= 4a^3 (C)

8.
CuCO3 => Cu 2+ + CO3 2-

Ksp= [Cu 2+][CO3 2-]
10^-10= S . S
S= 10^-5 (B)

9.
BaSO4 => Ba^2+ + SO4 2-

H2SO4 => 2H+ + SO4 2-
Jika molaritas H2SO4 = 0,01 molar
Maka molaritas SO4 2- = 0,01 molar

Ksp= [Ba^2+][SO4 2-]
10^-8 = S . 0,01
S= 10^-6 (C)

10.