KUNCI JAWABAN ESSAY

ESSAY
1.a). Ag2CrO4 2Ag+ + CrO42- ……..2 b). Ba3(PO4)2 3Ba2+ + 2 PO43-……………………………2
Ksp = 22.11.s3 Ksp = 33.22.s5
= 4s3 ……………………2 = 108s5…………………2
2. Dik : (NH4)2SO4
pH=5 Vol =100 ml
Ka = 1.10-5
Dit ; gram (NH4)2SO4 ……………………………………skor 1
Jwb : ops….Garam asam (BL + AK )
Rumus = pH = ½(14 - pKb - Log M garam)….skor 1
5= ½(14 - 5 – Log.M garam )
10 = 9 – log.M garam
M garam = 0,1 M………………………………….2
(NH4)2SO4 2NH4+ + SO42-
……? 0,1M
Maka (NH4)2SO4 = ½ x 0,1 M
= 0,05 M……………………………..2
M = gram/Mr . 1000/ml
Gram = M. Mr. ml
1000
= 0,05.132
10
= 0,66 gram……………………..2
3. Dik : L(OH)3 pH=10
Dit : Ksp………………………………………………………………..1
Jwb : ops…..basa, pOH= 14 - pH
pOH = 14 – 10
= 4
OH- = 10-4 …………………………………1
L(OH)3 L3+ + 3OH+
…..? 10-4
Maka L3+ = 1/3 . 10-4 ………………………………….2
Rumus Ksp= (L3+)( OH- )3 …………………………...2
= (1/3.10-4)(10-4) 3
= 3,3.10-17 …………………………………..3