• Once the standard electrode potentials (E^?) of the half-cells are determined, the?standard cell potential?(E_cell^?) can be calculated by?subtracting?the?less?positive?E^??from the?more positive?E^??value
  • The half-cell with the more positive?E^??value will be the?positive?pole
  • The half-cell with the less positive?E^??value will be the?negative?pole

Worked example: Calculating the standard cell potential

Answer

• Step 1:?Calculate the standard cell potential

E_cell^??= (+0.34) - (-0.76)

= +1.10 V

The voltmeter will therefore read off a value of 1.10 V

• Step 2:?Determine the positive and negative polesThe Cu²⁺/Cu? half-cell is the?positive?pole as its?E^??is more positive than the?E^??value of the Zn²⁺/Zn half-cell