Analytical ChemistryHard
Question
A solution containing SCN- ions can be used to test one or more out of : Fe3+, Co2+ , Cu2+, Ag+ and Hg2+.
Options
A.Fe3+ and Co2+ only
B.Co2+, Cu2+, Ag+ and Hg2+
C.Fe3+ , Cu2+, Co2+ and Hg2+
D.All
Solution
CoCl2 + 4NH4SCN 
(NH4)2 [Co(SCN)4] (blue colour in ethereal layer) + 2NH4Cl.
Cu2+ + 3SCN- → CuSCN↓ (white) + (SCN)2.
FeCl3 + 3NH4SCN
Fe(SCN)3 (blood red colour) + 3NH4Cl.
Ag+ + SCN- → AgSCN ↓ (white).
Co2+ + 4SCN- + Hg2+ → Co[Hg(SCN)4] ↓ (deep blue).
(NH4)2 [Co(SCN)4] (blue colour in ethereal layer) + 2NH4Cl.Cu2+ + 3SCN- → CuSCN↓ (white) + (SCN)2.
FeCl3 + 3NH4SCN
Fe(SCN)3 (blood red colour) + 3NH4Cl.Ag+ + SCN- → AgSCN ↓ (white).
Co2+ + 4SCN- + Hg2+ → Co[Hg(SCN)4] ↓ (deep blue).
Create a free account to view solution
View Solution FreeMore Analytical Chemistry Questions
Ammonium salts on heating with slaked lime liberates a colourless gas (X). Identify the correct statement for gas (X)....A black sulphide is formed by the action of H2S on :...H2S in the presence of HCl precipitates II group but not IV group because :...Fe2+ does not give prussian blue colour with K4[Fe(CN)6] but on its reaction with (X), prussian blue colour appears (X) ...Yellow ammonium sulphide solution is a suitable reagent for the separation of :...