Question

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

• A. $NaCl+KCl+KF$
• B. $NaCl$
• C. $NaOH+KCl+KF$
• D. $NaCl+NaOH$

Answer 1

The correct option is A $NaCl+KCl+KF$

In Down's process, molten sodium chloride (common salt) is electrolyzed using a graphite anode and a ring-shaped iron cathode. The two electrodes are separated by a wire gauge partition to avoid the mixing of sodium and chlorine so formed.

As sodium chloride melts at a very high temperature of $1085K$, a mixture containing sodium chloride, potassium chloride and potassium fluoride $(NaCl+KCl+KF)$ is employed. This mixture melts at about $(850-875)K$.