Summary Qualitative Analysis of Group II Cations

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