Question

An electrochemical cell stops working after sometime because:-

• A. Electrode potential of both the electrodes becomes zero
  
• B. Electrode potential of both the electrodes becomes equal
  
• C. The reaction starts proceeding in opposite direction
  
• D. None of these

Answer 1

The correct option is B Electrode potential of both the electrodes becomes equal


Oxidation happens at the anode and reduction at the cathode due to a potential difference between the two electrodes. As the reaction proceeds, these potentials come close to each other until they become equal. When this happens, no more electrons flow - as current exists only when there is a potential difference. This is when the cell stops working.