Which one of the following electrolytes is used in Down's process of extracting sodium metal?

Step-by-step solution

Sodium metal is manufactured by the electrolysis of fused sodium chloride mixed with KCl and KF . On electrolysis At iron cathode. Na ⁺+e⁻ Na (s) (metallic sodium) At graphite anode 2 Cl ⁻ Cl ₂(g)+2 e⁻ NaCl melts at 800^ C . It is difficult to attain and maintain its melting point. So, KCl and KF are mixed to lower the melting point of NaCl to about 600^ C . KCl and KF are themselves not electrolysed under the voltage conditions used for sodium.