1.
Buatlah tabel reaksi identifikasi kation untuksetiap golongan sesuai dengan pereaksi
pereaksi yang digunakan pada tabel dibawah ini (lihat diktat kimia dasar dan buku Vogel
kualitatif)
2. Tulis semua reaksi yang terjadi antara pereaksi – pereaksi yang digunakan dan kation
– kationnya
Kation Golonga I
Ag+
1) HCL + Ag+ → AgCl ↓ + Cl-
2) NaOH + Ag+ → AgOH ↓ + Cl-
AgOH↓ + NaOH ↛
3) NH4OH + Ag+ → AgOH↓ + NH4+
AgOH↓ + NH4OH → [Ag(OH)2]- + NH4+
4) KI + Ag+ → AgI ↓+ K+
AgI↓ + KI ↛
5) K2Cr O4 + 2 Ag+ → Ag2CrO4 + 2K+
Ag2CrO4 ↓ + NH4OH
Ag2CrO4 ↓ + HCL → AgCl ↓ + H2CrO4
6) H2SO4 + 2Ag+ → Ag2SO4 + 2H+
Pb2+
1) 2HCL + Pb2+ → PbCl2 ↓ + 2H+
2) 2NaOH + Pb2+ → Pb(OH)2 ↓ + 2Na+
Pb(OH)2 ↓ + NaOH → Na+ + [Pb(OH)3]+
3) NH4OH + Pb2+ → Pb(OH)2 ↓ + NH4+
Pb(OH)2 ↓ + NH4OH ↛
4) 2KI + Pb2+ → PbI2 ↓ + 2K+
Pb I2 ↓ + KI ↛
5) K2CrO4 + Pb2+ → PbCrO4 ↓ + 2K+
PbCrO4 ↓ + NH4OH
PbCrO4 ↓ + HCL
6) H2SO4 + Pb2+ → PbSO4 ↓ + 2H+
Hg22+
1) 2HCL + Hg22+ → HgCL2 ↓ + 2H+
2) 2NaOH + Hg22+ → Hg2(OH)2 ↓ + 2Na+
Hg2(OH)2 ↓ + NaOH ↛
3) 2NH4OH + Hg22+ → Hg2(OH)2 ↓ + 2NH4+
Hg2(OH)2 ↓ + NH4OH
4) 2KI + Hg22+ → Hg2I2 ↓ + 2NH4+
Hg2I2 ↓+ KI → [Hg2I4]- + K+
5) K2CrO4 + Hg22+ → Hg2CrO4 ↓ + 2K+
Hg2CrO4 ↓ + 2NH4OH → (NH4)2CrO4 ↓ + Hg2(OH)2
Hg2CrO4 ↓ + HCL →
H2SO4 + Hg22+ →
KATION GOLONGAN II
BI3+
1) NaOH
Bi3+ + 3NaOH → Bi(OH)3 + 3Na+
2) NH4OH
Bi3+ + 3NH4OH → Bi(OH)3 + 3NH4+
3) KI
Bi3+ + 3KI = Bi I3 + 3K+
4) Na2S
Bi3+ + 3Na2S → BiS3 + 3Na2+
Cu2+
1) NaOH
Cu2+ + 2NaOH → Cu(OH)2 ↓ + 2Na+
2) Cu(OH)2 + NaOH → Na[Cu(OH)3]
3) NH4OH
Cu2+ + 2NH4OH → Cu(OH)2 ↓ + 2NH4+
Cu(OH)2 + NH4OH → NH4[Cu(OH)3]
4) KI
Cu2+ + 2KI → Cu I2 ↓ + 2K+
Cu I2 + KI → K(Cu I2)
Cd