A:向Ba(OH)2溶液中逐滴加入NH4HSO4溶液至刚好沉淀完全:Ba2++2OH﹣+H++SO42﹣+NH4+=BaSO4↓+NH3•H2O+H2O
B:硫化钠的水解:S2﹣+2H2O⇌H2S+2OH﹣
C:向Fe(NO3)3溶液中加入过量的HI溶液:Fe3++3NO3﹣+10I﹣+12H+=5I2+Fe2++3NO↑+6H2O
D:NaHCO3溶液中滴加少量澄清石灰水:2HCO3﹣+Ca2++2OH﹣=CaCO3↓+2H2O+CO32﹣
解决这种水资源地区分布不均的有效措施是( )