Electrochemistry, galvanic cells and redox potential
≈ 50 minElectrochemistry, galvanic cells and redox potential
Electrochemistry links redox reactions to electrical energy. In a galvanic cell, a spontaneous redox reaction drives electron flow through an external circuit. Oxidation occurs at the anode and reduction at the cathode; in a galvanic cell the anode is negative and cathode positive. Electrons travel from anode to cathode through the wire, while ions move through a salt bridge or porous barrier to maintain charge balance. Standard electrode potentials compare reduction tendencies. Use Ecell = E°cathode − E°anode when the listed values are standard reduction potentials, and explain why a positive Ecell indicates a spontaneous cell reaction under standard conditions.
Work it through
For Zn|Zn²⁺ and Cu²⁺|Cu, E°(Cu²⁺/Cu) = +0.34 V and E°(Zn²⁺/Zn) = −0.76 V. Copper is reduced at the cathode and zinc is oxidised at the anode. E°cell = 0.34 − (−0.76) = +1.10 V. The positive result matches the familiar spontaneous zinc-copper cell.
Mastery target
Identify anode, cathode, electron flow and ionic balance in a galvanic cell, then calculate and interpret a standard cell potential.
Where does oxidation occur in a galvanic cell?
Name the key chemistry term from Electrochemistry, galvanic cells and redox potential that best fits the explanation and visual model.
Given E°cathode = +0.34 V and E°anode = −0.76 V, calculate E°cell in V.
Which statement corrects a common misunderstanding in Electrochemistry, galvanic cells and redox potential?