A.
AlCl 3 溶液与烧碱溶液反应,当n(OH - ):n(Al 3+ )=7:2时,2Al 3+ + 7OH - =Al(OH) 3 ↓+ AlO 2 - + 2H 2 O
B.
CuCl 2 溶液与NaHS溶液反应,当n(CuCl 2 ):n(NaHS)=1:2时Cu 2+ +2HS - =CuS↓+H 2 S↑
C.
Cl 2 与FeBr 2 溶液反应,当n(Cl 2 ):n(FeBr 2 )=1:1时,2Fe 2+ + 4Br - +3Cl 2 =2 Fe 3+ + 2Br 2 + 6Cl -
D.
Fe与稀硝酸反应,当n(Fe):n(HNO 3 )=1:2时,3 Fe +2NO 3 - +8H + =3Fe 2+ +2NO↑+4H 2 O