Question

Write electrode reaction during electrolysis of molten kcl

Answer 1

Answer:

 2K+ + 2e- → 2K (potassium metal at the (-)cathode). 2Cl- - 2e- → Cl2 (chlorine gas at the (+)anode). ... Chloride ions lose electrons (oxidation) to form chlorine atoms.

Answer 2

Overall reaction: $2K^+_{(l)}+2Cl^-_{(l)}$ → $2K_{(s)}+Cl_{(2)(g)}$

First, consider the chemical reaction for the decomposition of molten KCl.

 ⇒ $KCl_{(molten)}$ → $K^+_{(l)}+Cl^+_{(l)}$

 

Two steps are involved for the outcome of the overall reaction:

1. Reaction at Cathode:

⇒ $2K^+_{(l)}+2e^-$ → $2K_{(s)}$

The above-mentioned reaction undergoes a reduction reaction.

2. Reaction at Anode:

⇒ $2Cl^-_{(l)}$ → $2Cl_{(g)}+2e^-$

⇒ $2Cl_{(g)}$ → $Cl_{(2)(g)}$

The above reaction involves two steps in which chlorine gains two electrons and converts from liquid to gaseous phase. It undergoes an oxidation reaction.

∴The overall reaction: $2K^+_{(l)}+2Cl^-_{(l)}$ → $2K_{(s)}+Cl_{(2)(g)}$