At an electrode–electrolyte interface, metal ions from the solution tend to deposit on the metal electrode, while metal atoms of the electrode tend to go into the solution as ions. At equilibrium there is a separation of charges. What is the potential difference that develops between the electrode and the electrolyte called?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Electrode potential
Deposition of metal ions tries to make the electrode positively charged, and loss of metal atoms as ions tries to make it negatively charged. Depending on which tendency is stronger, the electrode ends up positive or negative with respect to the solution. This potential difference between one electrode and its electrolyte is the electrode potential.
NCERT (2026-27 edition):
2.2 Galvanic Cells – “At each electrode-electrolyte interface there is a tendency of metal ions from the solution to deposit on the metal electrode trying to make it positively charged. At the same time, metal atoms of the electrode have a tendency to go into the solution as ions and leave behind the electrons at the electrode trying to make it negatively charged. At equilibrium, there is a separation of charges and depending on the tendencies of the two opposing reactions, the electrode may be positively or negatively charged with respect to the solution. A potential difference develops between the electrode and the electrolyte which is called electrode potential.”