Đáp án:

 a.

$MnO_2 + 4HCl đ \buildrel{{t^o}}\over\longrightarrow MnCl_2 + Cl_2 +2H_2O$

$3Cl_2 + 2Fe \buildrel{{t^o}}\over\longrightarrow 2FeCl_3$

$FeCl3 + 3NaOH →  Fe(OH)_3 + 3NaCl$

$Fe(OH)_3 +3HCl → FeCl_3 + 3H_2O$

$FeCl_3 + 3AgNO_3 → 3AgCl +Fe(NO_3)_3$

$2AgCl \buildrel{{t^o}}\over\longrightarrow 2Ag + Cl_2$

b.

$2KMnO4 + 16HCl đ \buildrel{{t^o}}\over\longrightarrow 2KCl + 2MnCl_2 +5Cl_2 +8H_2O$

$Cl_2 + H_2 \buildrel{{t^o}}\over\longrightarrow 2HCl$

$2HCl + CuO → CuCl_2 + H_2O$

$CuCl_2 + Ba(OH)_2 → Cu(OH)_2 + BaCl_2$

$BaCl_2 + H_2SO_4 → BaSO_4 + 2HCl$

c.

$2NaCl + H_2SO_4 đ \buildrel{{t^o}}\over\longrightarrow  Na_2SO_4 + 2HCl$

$2HCl \xrightarrow{{dp{\text{dd}}}} H_2 + Cl_2$

$3Cl_2 + 2Fe \buildrel{{t^o}}\over\longrightarrow 2FeCl_3$

$FeCl_3 + 3NaOH → 3NaCl + Fe(OH)_3$

$2NaCl + 2H_2O \xrightarrow[{cmn}]{{dp{\text{dd}}}} 2NaOH +Cl_2 + H_2$

$NaOH + HCl → NaCl + H_2O$

$Cl_2 + Ca \buildrel{{t^o}}\over\longrightarrow CaCl_2$

$CaCl_2 + 2AgNO_3 → 2AgCl + Ca(NO_3)_2$

$2AgCl \buildrel{{t^o}}\over\longrightarrow 2Ag+ Cl_2$

d.

$2NaCl + H_2SO_4đ \buildrel{{t^o}}\over\longrightarrow Na_2SO_4 + 2HCl$

$2HCl +2 K → 2KCl +H_2$

$2KCl \xrightarrow{{dpnc}}2K +Cl_2$

$Cl_2 + 2Na \buildrel{{t^o}}\over\longrightarrow 2NaCl$

$2NaCl + 2H_2O \xrightarrow[{cmn}]{{dp{\text{dd}}}} 2NaOH + Cl_2 + H_2$

$H_2 + Cl_2 \buildrel{{t^o}}\over\longrightarrow 2HCl$

$2HCl  \xrightarrow{{dp{\text{dd}}}} H_2 + Cl_2$

$Cl_2 + Cu \buildrel{{t^o}}\over\longrightarrow CuCl_2$

$CuCl_2 + 2NaOH → 2NaCl + Cu(OH)_2$

$Cu(OH)_2 + H_2SO_4 → CuSO_4 + 2H_2O$

$CuSO_4 + 2KOH → K_2SO_4 + Cu(OH)_2$

$K_2SO_4 + Ba(NO_3)_2 → 2KNO_3 + BaSO_4$