Basic Concepts of Inorganic Chemistry, 2nd Edition

20

Analytical Chemistry (Salt Analysis)

Every salt contains a cation and an anion. The cation of a salt is called basic radical and the anion of a salt is called acid radical.

 

Table 20.1

Salt	Cation or Basic radical	Anions or Acid radical
NaCl	Na+	Cl−
BaSO4	Ba+2	SO4−2

The analysis is, therefore, performed in two steps:

1. Tests for acid radicals.
2. Tests for basic radicals

In practice, tests for acid radicals are carried out first and after that basic radical are tested.

TEST FOR ACiD RADICALS

It is carried out in two steps:

1. Preliminary tests
2. Solution tests

Preliminary tests

Acid radicals are conjugate bases of acids.

 

Table 20.2

Acid	Acid radical
H2SO4	HSO4− or SO4−2
HCl	Cl−
HNO3	NO3−
H2S	S−2

The test reagent is ...