Question

Which of the substances Na, Hg, S, Pt and Graphite can be used as electrolytic cells having aqueous solutions?
A. Hg, Pt and graphite
B. Na and Hg
C. Pt and graphite only
D. Na and S only

Answer 1

Hint: The electrochemical cell defines the cell that produces electricity from the chemical reaction. A dry cell is used mostly in the portable electronic device and equipment of the house. The dry cell that is used in common consists of zinc and carbon electrodes.

Complete Step by Step Solution:
In an electrolytic cell, the electrodes are chosen in such a way that they do not undergo reaction with the ions present in the solution. Here, we have to identify the electrode that does not undergo reaction with water.

Mercury (Hg) does not undergo a reaction with water. Therefore, its use as an electrode in electrolytic cells possessing aqueous solutions is possible. Similarly Platinum (Pt) is an inert metal. So, it also does not undergo reaction with water. Therefore,its use as an electrode in electrolytic cells possessing aqueous solutions is possible.

Graphite also does not undergo a reaction with water. Therefore, its use as an electrode in electrolytic cells possessing aqueous solutions is possible. But , Sodium (Na)and sulphur(S) undergo a reaction with water. Therefore, it cannot be used as an electrode in electrolytic cells possessing aqueous solutions.
Hence, option A is right.

Note: In the electrochemical cells, platinum is used because of its nature to resist oxidation. It does not undergo chemical reactions easily. So, it will not become part of the redox reactions occurring at the electrochemical cells.