Analytical ChemistryHard
Question
A coloured solution of a salt gives following reactions.
(i) It gives white precipitate with sodium hydroxide which becomes brown on exposure to air.
(ii) It gives white precipitate with ammonia solution which is soluble in ammonium salts.
(iii) Its acidified solution containing a few drops of dilute AgNO3 on boiling with ammonium peroxodisulphate gives a reddish violet solution. The cation of the salt is :
(i) It gives white precipitate with sodium hydroxide which becomes brown on exposure to air.
(ii) It gives white precipitate with ammonia solution which is soluble in ammonium salts.
(iii) Its acidified solution containing a few drops of dilute AgNO3 on boiling with ammonium peroxodisulphate gives a reddish violet solution. The cation of the salt is :
Options
A. Mn2+
B.Zn2+
C.Al3+
D.Ni2+
Solution
(i) Mn2+ + 2OH- → 2Mn(OH)2↓ (white)
2Mn(OH)2↓+ O2 → MnO(OH)2↓ (brown)
(ii) Mn2+ + 2NH3 + 2H2O ⇋ Mn(OH)2↓ + 2NH4+
with NH4+ the reaction proceeds towards the left.
(iii) 2Mn2+ + 5S2O82- → 2MnO4- + 10SO42- + 16H+
2Mn(OH)2↓+ O2 → MnO(OH)2↓ (brown)
(ii) Mn2+ + 2NH3 + 2H2O ⇋ Mn(OH)2↓ + 2NH4+
with NH4+ the reaction proceeds towards the left.
(iii) 2Mn2+ + 5S2O82- → 2MnO4- + 10SO42- + 16H+
Create a free account to view solution
View Solution FreeMore Analytical Chemistry Questions
A metal nitrate reacts with KI solution to give yellow precipitate which on addition of excess of more concentrated solu...H2S does not produce metallic sulphide with :...Potassium chromate solution is added to an aqueous solution of a metal chloride. The yellow precipitate thus obtained is...Original solution of salt or mixture should not be prepared in concentrated HNO3 because it :...Which onr amongst the following pairs of ions cannot be separated by H2S in dilute HCL ?...