(1)N 2;3Cu+8H ++2NO 3 -=3Cu 2++2NO↑+4H 2O
(2)S;火药、硫酸
(3)Ca(OH) 2+2NH 4Cl=2NH 3↑+ CaCl 2+2H 2O
(4)H 2S;2H 2S+SO 2=3S↓+2H 2O