What is the factor responsible for the conductance of Electrolytic conductors?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Due to movement of ions towards oppositely charged electrodes.
Metals carry current by moving electrons; an electrolytic (ionic) conductor, such as a solution of \( \ce{NaCl} \) in water, carries it by the movement of ions.
When a potential difference is applied, the ions move towards the electrodes of opposite charge. In aqueous \( \ce{NaCl} \), the \( \ce{Na^+} \) ions move to the cathode (negative electrode) and the \( \ce{Cl^-} \) ions move to the anode (positive electrode).
This flow of ions in opposite directions carries the current through the solution, so electrolytic conductance is due to the movement of ions towards oppositely charged electrodes.
Why the other options are incorrect
Option (1) Due to mobility of electrons. — Incorrect.
Moving electrons carry the current in metallic (electronic) conductors, not in electrolytes.
In an electrolytic solution, electrons are exchanged only at the surfaces of the electrodes; inside the solution the charge is carried by ions.
Option (3) Due to movement of protons. — Incorrect.
Protons are only one kind of ion, \( \ce{H^+} \), present in acidic solutions.
Electrolytic conductance comes from all the cations and anions present; a solution of \( \ce{NaCl} \) or \( \ce{KCl} \) conducts well with almost no \( \ce{H^+} \) ions in it.
NCERT (2026-27 edition):
Conductance of Electrolytic Solutions – “… The conductance of electricity by ions present in the solutions is called electrolytic or ionic conductance.”