Could someone give me a list of precipitates for the following ions : #Hg^+,Hg_2^{2+},Cr^{2+},Cr^{3+},Mn^{2+,3+,4+,5+,6+,7+},Co^{2+,3+},Ni^{2+,3+}#(the list must include the precipitate's colour too) ?

Question

Luna Chen · Accepted Answer

Are you joking? Have you not got an inorganic text?

For evaluating solubilities in aqueous solution, the following general guidelines apply: All the salts of the #"alkali metals"# and #"ammonium"# are soluble; All #"nitrates"#, and #"perchlorates"# are soluble. All #"halides"# are soluble EXCEPT for # AgX, Hg_2X_2, PbX_2"#. All #"sulfates"# are soluble EXCEPT for #PbSO_4, BaSO_4, HgSO_4#. All #"oxides, carbonates, and hydroxides are insoluble"#. All #"sulfides"# are insoluble. The given rules follow a hierarchy. Alkali metal and ammonium salts tend to be soluble in all circumstances. The one exception to this rule is #K^(+)""^(-)BPh_4# and #NH_4^(+)""^(-)BPh_4#, both of which are as soluble as bricks. #Na^+""^(-)BPh_4#, the which has some aqueous solubility, is sold as #"kalignost"#, i.e. #"potassium recognizer"#............. You've asked a far too general question.

Cooper Adams · Answer

undefined Here is a list of precipitates for the given ions along with their colors:

1. Hg^+ (Mercury(I)): No common precipitate.
2. Hg_2^{2+} (Mercury(II)): No common precipitate.
3. Cr^{2+} (Chromium(II)): No common precipitate.
4. Cr^{3+} (Chromium(III)): Forms a green precipitate with hydroxide ions (Cr(OH)_3).
5. Mn^{2+} (Manganese(II)): Forms a white precipitate with hydroxide ions (Mn(OH)_2).
6. Mn^{3+} (Manganese(III)): Forms a brown precipitate with hydroxide ions (MnO(OH)).
7. Mn^{4+} (Manganese(IV)): Forms a brown precipitate with hydroxide ions (MnO_2).
8. Mn^{5+} (Manganese(V)): No common precipitate.
9. Mn^{6+} (Manganese(VI)): No common precipitate.
10. Mn^{7+} (Manganese(VII)): No common precipitate.
11. Co^{2+} (Cobalt(II)): Forms a pink precipitate with hydroxide ions (Co(OH)_2).
12. Co^{3+} (Cobalt(III)): No common precipitate.
13. Ni^{2+} (Nickel(II)): Forms a green precipitate with hydroxide ions (Ni(OH)_2).
14. Ni^{3+} (Nickel(III)): No common precipitate.

Please note that the colors of precipitates can vary depending on the conditions and other ions present in the solution.