ルクランシェ電池
Mn 2 O 3 ( s ) + 3 H 2 O + 2 e − ⟶ 2 Mn ( OH ) 2 ( s ) ↓ + 2 OH − {\displaystyle {\ce {Mn2O3(s)\ +3H2O\ +2{\mathit {e}}^{-}->2Mn(OH)2(s)\downarrow +2OH^{-}}}}
Zn ( s ) + 2 MnO 2 ( s ) + 2 NH 4 Cl ( aq ) + 2 H 2 O ( l ) ⟶ ZnCl 2 ( aq ) + 2 Mn ( OH ) 2 ( s ) + 2 NH 3 ( aq ) {\displaystyle {\ce {Zn(s)\ + 2 MnO2(s)\ + 2 NH4Cl(aq)\ + 2H2O(l) -> ZnCl2(aq)\ + 2Mn(OH)2(s)\ + 2 NH3(aq)}}}
半反応式:
カソード側: MnO 2 ( s ) + NH 4 + ( aq ) + e − ⟶ MnO ( OH ) ( s ) + NH 3 ( aq ) {\displaystyle {\ce {MnO2(s)\ +NH4^{+}(aq)\ +{\mathit {e}}^{-}->MnO(OH)(s)\ +NH3(aq)}}}
アノード側: Zn ( s ) ⟶ Zn 2 + ( aq ) + 2 e − {\displaystyle {\ce {Zn(s)\ ->Zn^{2}+(aq)\ +2{\mathit {e}}^{-}}}}
2MgO+2NH4Cl+Zn→Mn2O3+Zn(NH3)2Cl2+H2O