Electrode potentials and electrochemical cells (A-level only) common mistakes

Common mistakes

• Confusing electrode potentials

  Students often confuse the standard electrode potential of the SHE with other half-cell potentials.

  Fix itRemember that the SHE is defined as 0.00 V and serves as a reference point for all other measurements.

• Confusing oxidation and reduction

  Students often mix up which species is oxidized and which is reduced in a redox reaction.

  Fix itRemember that oxidation is the loss of electrons and reduction is the gain of electrons. Use the standard electrode potentials to identify the anode and cathode.

• Incorrectly identifying anode and cathode

  Students often confuse which electrode is the anode and which is the cathode.

  Fix itRemember that the anode is where oxidation occurs (loss of electrons) and the cathode is where reduction occurs (gain of electrons).

• Confusing anode and cathode

  Students often confuse the anode and cathode in electrochemical cells.

  Fix itRemember that oxidation occurs at the anode and reduction occurs at the cathode.

• Confusing Oxidation and Reduction

  Students often confuse oxidation with reduction.

  Fix itRemember that oxidation involves loss of electrons, while reduction involves gain of electrons.

• Incorrectly identifying the anode and cathode

  Students often confuse which electrode is the anode and which is the cathode.

  Fix itRemember that the anode is where oxidation occurs (loss of electrons) and the cathode is where reduction occurs (gain of electrons).

• Confusing Oxidation and Reduction

  Students often confuse which species is oxidized and which is reduced in redox reactions.

  Fix itRemember that oxidation involves loss of electrons and reduction involves gain of electrons. Use the mnemonic 'OIL RIG' (Oxidation Is Loss, Reduction Is Gain).

• Confusing fuel cells with batteries

  Students often confuse the operation of fuel cells with that of batteries, thinking they are the same.

  Fix itRemember that fuel cells convert chemical energy directly into electricity, while batteries store energy chemically and release it.

• Confusing standard cell potential with actual cell potential

  Students often assume that the standard cell potential is the same as the cell potential under non-standard conditions.

  Fix itRemember that the Nernst equation must be used to calculate the actual cell potential based on concentrations.