Thursday, January 17, 2008

Ch.18.Exercises in Inorganic Chemistry - Core Points for Revision


Principles of qualitative analysis: Groups I to V (only Ag+, Hg2+, Cu2+, Pb2+, Bi3+, Fe3+, Cr3+, Al3+, Ca2+, Ba2+, Zn2+, Mn2+ and Mg2+); Nitrate, halides (excluding fluoride), sulphate, sulphide and sulphite.


Characteristic tests of Anions

Sulphide: With dilute H2SO4, H2S is evolved, which turns lead acetate paper black.

Sulphite: With dilute H2SO4, SO2 is released.

Sulphate: Soluble sulphate salt gives white precipitate of BaSO4 with BaCl2 solution which is insoluble in concentrated HCl.

Nitrite: With dilute H2SO4, nitric oxide is released.

Chloride: With conc. H2SO4,HCl gas is released.

Bromide: With conc. H2SO4,brownish vapours of Br2 are released.

Iodide: With conc H2SO4,violet vapours of I2 are released.

Nitrate: With conc H2SO4, brown vapours of NO2 are released.

Analysis of Cations

Group I cations: Ag, Hg, Pb

Group II : Hg, Cu, Bi, Cd, As, Sb, Sn

Group III: Fe, Cr, Al,

Group IV: Co, Mn, Ni, Zn

Group V: Ba, Sr, Ca

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