Question

write down the cell reactions occuring in following cells?

1)(Pt)H₂/H⁺//Cu²⁺/Cu 2)Cd/Cd²⁺//Cl^-/AgCl/Ag 3)Pt/ClO₃^-_,Cl^-//ClO₂^-/Cl₂(Pt)

Answer 1

1)(Pt)H₂/H⁺//Cu²⁺/Cu
At anode:
$H_2\to 2e+2H^{+}$
At cathode:
$C{u}^{2+}+2e\to Cu$
Overall reaction:
$H_2+C{u}^{2+}\to 2H^{+}+Cu$
2)Cd/Cd²⁺//Cl^-/AgCl/Ag
At anode:
$Cd\to C{d}^{2+}+2e$
At cathode:
$2AgCl+2e\to 2Ag+2C{l}^{-}$
Overall reaction:
$Cd+2AgCl\to C{d}^{2+}+2Ag+2C{l}^{-}$
3)Pt/ClO₃ ^- ,Cl^-//ClO₂ ^-/Cl₂(Pt)
At anode:
$C{l}^{-}\to Cl{O}_3^{-}+6e$
At cathode:
$2Cl{O}_2^{-}+6e\to C{l}_2$
Overall reaction:
$C{l}^{-}+2Cl{O}_2^{-}\to Cl{O}_3^{-}+C{l}_2$