Qualitative Analysis of Group II Cations
I. Objectives
● To confirm the presence of the group II cations from a stock solution using precipitation
tests.
● To analyze the characteristics of the cations while undergoing different processes.
II. Introduction
Group II cations is divided into two subgroups, copper and arsenic subgroups. The copper
subgroup consists of Hg2+, Pb2+, Bi3+, Cu2+, and Cd2+. Their sulfides are not acidic thus,
they are insoluble in KOH solution. The arsenic subgroup consists of As3+, Sn4+, and Sb3+.
They form acidic sulfides that are soluble in KOH. To confirm the presence of group II cations in
a solution, precipitation reactions are done. Precipitates are insoluble ionic solid products of a
reaction formed when certain cations or anions combine in an aqueous solution. It produces
different colors depending on the ions present.
III. Materials & Equipment
Reagents Laboratory Glasswares & Lab Kit
Apparatus
H20 Beaker Bond Paper
HNO3 Clamps/Tongs Gloves
NH3 Centrifuge Lab Gown
HCI Casserole Marker
Thioacetamide Dropper Masking Tape
NH4Cl Hot Plate Scissors
KOH Spot Plate
K2CrO4 Stirring Rod
HgCl Test Tube
KCN Test Tube Rack
AgNO3 Wash Bottle
Aqua Regia
SnCl2
H2SO4
I. Objectives
● To confirm the presence of the group II cations from a stock solution using precipitation
tests.
● To analyze the characteristics of the cations while undergoing different processes.
II. Introduction
Group II cations is divided into two subgroups, copper and arsenic subgroups. The copper
subgroup consists of Hg2+, Pb2+, Bi3+, Cu2+, and Cd2+. Their sulfides are not acidic thus,
they are insoluble in KOH solution. The arsenic subgroup consists of As3+, Sn4+, and Sb3+.
They form acidic sulfides that are soluble in KOH. To confirm the presence of group II cations in
a solution, precipitation reactions are done. Precipitates are insoluble ionic solid products of a
reaction formed when certain cations or anions combine in an aqueous solution. It produces
different colors depending on the ions present.
III. Materials & Equipment
Reagents Laboratory Glasswares & Lab Kit
Apparatus
H20 Beaker Bond Paper
HNO3 Clamps/Tongs Gloves
NH3 Centrifuge Lab Gown
HCI Casserole Marker
Thioacetamide Dropper Masking Tape
NH4Cl Hot Plate Scissors
KOH Spot Plate
K2CrO4 Stirring Rod
HgCl Test Tube
KCN Test Tube Rack
AgNO3 Wash Bottle
Aqua Regia
SnCl2
H2SO4
