A. B. C. D. 3. C AHClNaOHBaClNaSO 22 4 BHCl Ba(OH)NaSOBaCl 2242 CHSOBa(OH)NaSOBaCl 242242 DHSONaOHBaClNaSO 2422 4 4.() D AXB CCa(OH)2CaO D 5.()FeFeOCuOC Fe C CuO:. FeCuO A A1B2C3D4 6. A D ABC Ca(OH)COHFe 222 CONaOHOHCl Na232 HSOCaClCuOCuSO 2424 7.() BaClAgNOHClNaOH 23 C XYZ AHSOHHO 2422 BCuSOCuClCu(OH) 422 CHOHCO 222 DCa(OH)NaOHNaCO 223 8.() +2AB;C ACD DE C ABC