The solid commonly used as an inactive electrode in electrochemical cells is graphite (option B)
What are inactive electrodes?
Inactive electrodes, also known as inert electrodes, serve solely to conduct electrons between the electrolyte and the external circuit in electrochemical cells, without engaging in the cell's chemical reactions.
An ideal inactive electrode displays specific properties:
High electrical conductivity: Effectively conducts electrons.
Chemical stability: Avoids reactions with the electrolyte or other electrodes.
Insolubility in the electrolyte: Remains undissolved in the solution.
Cost-effectiveness and availability.
Graphite embodies these qualities:
Exceptional electrical conductivity: One of the most proficient conductors among common materials.
Chemical inertness: Resistant to oxidation or reduction in typical electrochemical conditions.
Insolubility in most electrolytes: Does not dissolve in water or common aqueous solutions.
Cost-effectiveness and widespread availability: Relatively inexpensive and easily procurable.