Question

Which among the following represents the correct half-reaction for the respective electrolyte?

[1 mark]

• A. Electrolyte: KBr
  Cathode: $K^{+}$ + $e^{-}$ → K
  Anode: ${Br}^{-}$→ Br - $e^{-}$
• B. Electrolyte: NaCl
  Cathode: ${Na}^{+}$ + $e^{-}$→ Na
  Anode: ${Cl}^{-}$ + $e^{-}$→ Cl
• C. Electrolyte: KBr
  Cathode: $K^{+}$ + $e^{-}$ → K
  Anode: ${Br}^{-}$→ Br + $e^{-}$
• D. Electrolyte: NaCl
  Cathode: ${Na}^{+}$ - $e^{-}$→ Na
  Anode: ${Cl}^{-}$ + $e^{-}$ → Cl

Answer 1

The correct option is C Electrolyte: KBr

Cathode: $K^{+}$ + $e^{-}$ → K
Anode: ${Br}^{-}$→ Br + $e^{-}$
We know that oxidation takes place at the anode.
Reactions at anode: ${Br}^{-}$→ Br + $e^{-}$
${Cl}^{-}$→ Cl + $e^{-}$

Reduction takes place at the cathode.
Reactions at cathode: $K^{+}$ + $e^{-}$ → K
${Na}^{+}$ + $e^{-}$ → Na