Question

The role of copper diaphragm in Whytlaw-Gray's method is:

• A. Preventing the corrosion of electrolytic cell
• B. Preventing the mixing of $H_2$ and $F_2$
• C. As anode
• D. As cathode

Answer 1

Answer: (B)

Preventing the mixing of $H_2$ and $F_2$

In this method, electrolysis is carried out in an electrically heated copper cell. The electrolytic is fused potassium hydrogen fluoride. The copper vessel serves as cathode also. The anode is made of graphite. The anode is surrounded by a copper diaphragm at the bottom.

This diaphragm prevents the mixing of $H_2$ and $F_2$ which react explosively if they come into contact. $F_2$, liberated at the anode is passed through the U - tube containing sodium fluoride.

Hence, option $B$ is correct.