c1: Điền chất có CTHH thích hợp vào chỗ trống hoàn thành các PTHH sau: 1. K+............-------->K2O 11. BaCO3+...........--------->BaCl2+CO2+H2O 2. Na2O+.............---------->NaCl + H2O 12.Al+FeCl2---------->AlCl3+............ 3. ............+ HCl---------->FeCl3+H2O 13.Fe(OH)3+HNO3---------->Fe(NO3)3+.............. 4. CuCl2+AgNO3--------->.............+Cu(NO3)2 14.CaCl2+Na3PO4---------->Ca3(PO4)2+............ 5. Fe+CuSO4---------->NaCl+................. 15.SO2+...............----------->SO3 6. BaCl2+Na2SO4----------->NaCl+............... 16.Na2CO3+BaCl2--------->BaCO3+................... 7.CH4+..............------------>CO2+H2O 17.C2H5O+O2----------->...............+H2O 8.H2+................------------>Pb+H2O 18. ..................+H2---------->NH3 9. KClO3--------------->KCl+................ 19.S+...............----------->H2S 10. ..............+H2SO4---------->MgSO4+H2 20. Fe+.............---------.>FeCl3