a,
$MnO_2+4HCl\to MnCl_2+Cl_2+2H_2O$
$2FeCl_2+Cl_2\to 2FeCl_3$
$FeCl_3+3KOH\to Fe(OH)_3+3KCl$
$Fe(OH)_3+3HCl\to FeCl_3+3H_2O$
$FeCl_3+3AgNO_3\to Fe(NO_3)_3+3AgCl$
$2AgCl\xrightarrow{{t^o}} 2Ag+Cl_2$
b,
$2KMnO_4+16HCl\to 2MnCl_2+2KCl+5Cl_2+8H_2O$
$H_2+Cl_2\xrightarrow{{t^o}} 2HCl$ 
$CuO+2HCl\to CuCl_2+H_2O$
$CuCl_2+Ba(OH)_2\to Cu(OH)_2+BaCl_2$
$BaCl_2+H_2SO_4\to BaSO_4+2HCl$
c,
$NaCl+H_2SO_{4_đ}\xrightarrow{{t^o}} NaHSO_4+HCl$
$MnO_2+4HCl\to MnCl_2+Cl_2+2H_2O$
$2FeCl_2+Cl_2\to 2FeCl_3$
$FeCl_3+3NaOH\to Fe(OH)_3+3NaCl$
$2NaCl+2H_2O\xrightarrow{{đpmn}} 2NaOH+H_2+Cl_2$
$NaOH+HCl\to NaCl+H_2O$
$2NaCl+2H_2O\xrightarrow{{đpmn}} 2NaOH+H_2+Cl_2$
$Ca+Cl_2\xrightarrow{{t^o}} CaCl_2$
$CaCl_2+2AgNO_3\to Ca(NO_3)_2+2AgCl$
$2AgCl\xrightarrow{{t^o}} 2Ag+Cl_2$
d,
$NaCl+H_2SO_{4_đ}\xrightarrow{{t^o}} NaHSO_4+HCl$
$HCl+KOH\to KCl+H_2O$
$2KCl\xrightarrow{{đpnc}} 2K+Cl_2$
$Cl_2+2Na\xrightarrow{{t^o}} 2NaCl$
$2NaCl+2H_2O\xrightarrow{{đpmn}} 2NaOH+H_2+Cl_2$
$H_2+Cl_2\xrightarrow{{t^o}} 2HCl$
$MnO_2+4HCl\to MnCl_2+Cl_2+2H_2O$
$Cu+Cl_2\xrightarrow{{t^o}} CuCl_2$
$CuCl_2+2NaOH\to Cu(OH)_2+2NaCl$
$Cu(OH)_2+H_2SO_4\to CuSO_4+2H_2O$
$CuSO_4+2KOH\to Cu(OH)_2+K_2SO_4$
$K_2SO_4+Ba(NO_3)_2\to BaSO_4+2KNO_3$ 

`a)`

`MnO_2+4HCl→MnCl_2+Cl_2+2H_2O`

`3Cl_2+2Fe→2FeCl_3(nhiệt độ)`

`FeCl_3+3NaOH→Fe(OH)_3+3NaCl`

`Fe(OH)_3+3HCl→FeCl_3+3H_2O`

`FeCl_3+3AgNO3→Fe(NO_3)_3+3AgCl`

`2AgCl→2Ag+Cl_2(nhiệt độ)`

`b)`

`2KMnO_4+16HCl→2KCl+2MnO_2+5Cl_2+8H_2O`

`Cl_2+H_2→2HCl(ánh sáng)`

`CuO+2HCl→CuCl_2+H_2O`

`CuCl_2+Ba(OH)_2→BaCl_2+Cu(OH)_2`

`BaCl_2+Na_2SO_4→BaSO_4+2NaCl`

`c)`

`NaCl+H_2SO_4→NaHSO_4+HCl`

`2HCl→H_2+Cl_2(điện phân)`

`3Cl_2+2Fe→2FeCl_3(nhiệt độ)`

`FeCl_3+3NaOH→Fe(OH)_3+3NaCl`

`2NaCl→2Na+Cl_2(đpnc)`

`Cl_2+Ca→CaCl_2(nhiệt độ)`

`CaCl_2+2AgNO_3→Ca(NO_3)_2+2AgCl`

`2AgCl→2Ag+Cl_2(nhiệt độ)`

`d)`

`NaCl+H_2SO_4→NaHSO_4+HCl`

`HCl+KOH→KCl+H_2O`

`2KCl→2K+Cl_2(đpnc)`

`Cl_2+2Na→2NaCl(nhiệt độ)`

`2NaCl+2H_2O→2NaOH+Cl_2+H_2(đpmn)`

`H_2+Cl_2→2HCl(ánh sáng)`

`2HCl→Cl_2+H_2(điện phân)`

`Cu+Cl_2→CuCl_2(nhiệt độ)`

`CuCl_2+2NaOH→Cu(OH)_2+2NaCl`

`Cu(OH)_2+H_2SO_4→CuSO_4+2H_2O`

`CuSO4+2KOH→K_2SO_4+Cu(OH)_2`

`K_2SO_4+Ba(NO_3)_2→2KNO_3+BaSO_4`