Which of the following is soluble in yellow ammonium sulphide?

Upon treatment with ammoniacal $H_2S$,the metal ion that precipitates as a sulfide is

$Fe$ (finely powdered) $+ HCl(dil.) \to P + Q\uparrow$. Compound $P$ does not precipitate with:

Match List-$I$ with List-$II$ and select the correct answer using the codes given below.

List-$I$ (Ion involved)	List-$II$ (Agent)
$(i) \, Ni^{2+}$	$(A).$ Sodium thiosulphate
$(ii) \, Ag^{+}$	$(B).$ Sodium nitroprusside
$(iii) \, Cu^{2+}$	$(C).$ Ammonia
$(iv) \, S^{2-}$	$(D).$ Dimethylglyoxime

Sodium carbonate cannot be used in place of ammonium carbonate for the precipitation of the fifth group radicals because

Three separate samples of a solution of a single salt gave these test results: one formed a white precipitate with excess ammonia solution,one formed a white precipitate with dilute $NaCl$ solution,and one formed a black precipitate with $H_2S$. The salt could be: