1.$4FeS_2$+$11O_2$$\xrightarrow[]{t^o}$$2Fe_2$$O_3$+$8SO_2↑$

2.$2Fe(OH)_3$$\xrightarrow[]{t^o}$$Fe_2$$O_3$+$3H_2O$

3.$SO_2$+$2H_2S$→3S↓+$2H_2O$

4.$3Fe_2$$O_3$+$H_2$$\xrightarrow[]{t^o}$$2Fe_3$$O_4$+$H_2O$

5.FeS+2HCl→$FeCl_2$+$H_2S↑$

6.$4Fe(OH)_2$+$O_2$+$2H_2O$→$4Fe(OH)_3↓$

7.$FeCl_2$+2NaOH→$Fe(OH)_2$+2NaCl 

8.$MnO_2$+4HBr→$Br_2$+$MnBr_2$+$2H_2O$

9.$Cl_2$+$SO_2$+$2H_2O$→2HCl+$H_2$$SO_4$

10.$Ca(OH)_2$+$2NH_4$$NO_3$→$2NH_3$+$Ca(NO_3)$$_2$+$2H_2O$

11.$Ca(H_2PO$$_4)$$_2$+$2Ca(OH)_2$→$Ca_3(PO$$_4)$$_2$+$4H_2O$

12.4$C_x$$H_y$$(COOH)_2$+(2x+y+2)$O_2$→(4x+8)$CO_2↑$+(2y+4)$H_2O$

13.$2KHCO_3$+$Ca(OH)_2$→$K_2$$CO_3$+$CaCO_3↓$+$2H_2O$

Đáp án+Giải thích các bước giải:

`4FeS_2 + 11O_2` $\xrightarrow[]{t^o}$ `8SO_2uparrow + 2Fe_2O_3`

`2Fe(OH)_3` $\xrightarrow[]{t^o}$ `Fe_2O_3 + 3H_2O`

`SO_2 + 2H_2S -> 3Sdownarrow + 2H_2O`

`3Fe_2O_3 + H_2` $\xrightarrow[]{t^o}$ `2Fe_3O_4 + H_2O`

`FeS + 2HCl -> FeCl_2 + H_2Suparrow`

`4Fe(OH)_2 + O_2 + 2H_2O -> 4Fe(OH)_3downarrow`

`FeCl_2 + 2NaOH -> Fe(OH)_2downarrow + 2NaCl`

`MnO_2 + 4HBr -> Br_2 + MnBr_2 + 2H_2O`

`Cl_2 + SO_2 + 2H_2O -> 2HCl + H_2SO_4`

`Ca(OH)_2 + 2NH_4NO_3 -> 2NH_3 + Ca(NO_3)_2 + 2H_2O`

`Ca(H_2PO_4)_2 + 2Ca(OH)_2 -> Ca_3(PO_4)_2 + 4H_2O`

`4C_xH_y(COOH)_2 + (2x+y+2)O_2 -> (4x+8)CO_2 + (2y+4)H_2O`

`2KHCO_3 + Ca(OH)_2 -> K_2CO_3 + CaCO_3 + 2H_2O`