Question

For extraction of sodium from $NaCl$, the electrolytic mixture $NaCl+{Na}_3{AlF}_6+{CaCl}_2$ is used. During extraction process, only sodium is deposited on cathode but $K$ and $Ca$ do not because:

• A. $Na$ is more reactive than $K$ and $Ca$
• B. $Na$ is less reactive than $K$ and $Ca$
• C. $NaCl$ is less stable than ${Na}_3{AlF}_6$ and ${CaCl}_2$
• D. the discharge potential of ${Na}^{+}$ is less than that of $K^{+}$ and ${Ca}^{2+}$ ions

Answer 1

The correct option is D the discharge potential of ${Na}^{+}$ is less than that of $K^{+}$ and ${Ca}^{2+}$ ions

As $K$ and $Ca$ are more reactive than $Na$ & they have less discharge potential than $Na$ so they will not discharge.