如何用一種試劑把下列每一組物質(zhì)分開?
(1)As2S3,HgS
(2)CuS,HgS
(3)Sb2S3,As2S3
(4)PbSO4,BaSO4
(5)Cd(OH)2,Bi(OH)3
(6)Pb(OH)2,Cu(OH)2
(7)SnS2,PbS
(8)SnS,SnS2
(9)ZnS,CuS
(10)Ag2S,MnS
沉淀第二組陽離子,調(diào)節(jié)酸度時:
(1)以HNO3代替HCl;
(2)以H2SO4代替HCl;
(3)以HAc代替HCl。將各發(fā)生什么問題?