The Cu2+ ion can be separated from Ag+,

Question

Ca2+, and K+ in aqueous solution by
1. precipitation of Cu2+ as Cu(OH)2(s) with
6 M NaOH(aq).
2. precipitation of Ag+, Ca2+, and K+ as
the carbonates.
3. None of these procedures will separate
Cu2+ from the other ions.
4. precipitation of Cu2+ as CuCl2(s) with 6
M HCl(aq).
5. precipitation of Cu2+ as CuS(s) at pH 1.

Answer 1

The Cu2+ ion can be separated from Ag+,
Ca2+, and K+ in aqueous solution by
1. precipitation of Cu2+ as Cu(OH)2(s) with 6 M NaOH(aq).
Cu(OH)2 will ppt but so will Ag(OH)2/Ag2O.

2. precipitation of Ag+, Ca2+, and K+ as
the carbonates.
CuCO3 will ppt with Ag2CO3 and K^+ will not\
3. None of these procedures will separateCu2+ from the other ions.
I think this is the best answer.

4. precipitation of Cu2+ as CuCl2(s) with 6 M HCl(aq).
Absolutely not. CuCl2 is soluble.

5. precipitation of Cu2+ as CuS(s) at pH 1.
The solubility of Ag2S and CuS are more or less the same at pH=1 so that will not separate the two.