jLYCEE DE KIGALI
SENIOR SIX PCB
QUALITATIVE ANALYSIS
The following tables summarize tests for common ions (anions & cations)
6) Ammonia solution
This reagent precipitates hydroxides. On adding excess some cation form soluble ammine complexes.
E
A. Anions
b
Note: Sulphite and Carbonate ions also give a white precipitate with barium ions but these precipitates
(unlike that of barium sulphate) are soluble in dilute acids. This is why you have to add dilute
hydrochloric acid as well as barium chloride solution.
SOME EXAMPLES OF PRACTICAL WORK ABOUT QUALITATIVE ANALYSIS
1) You are provided with substance Q which contains 2 cations and one anion. You are required to
identify the cations and anion in Q Carry out the following tests and record your observations and
deductions in the table below. Identify any gas evolves.
The formula for the compound is Fe SO4(NH4)2SO4 .n H2O, where n is the crystallization number.If n is
6, we get the Mohr salt.