Galvanic cell: the Daniell cell template

Daniell cell diagram with zinc anode (−) and copper cathode (+), electron flow in the wire, salt-bridge ion flow, half-equations, cell notation, E°cell = +1.10 V and ΔG° = −212 kJ mol⁻¹.

What the template shows

• Zn | Zn²⁺ ‖ Cu²⁺ | Cu: oxidation at the anode, reduction at the cathode, ions through the salt bridge
• salt bridge (KNO₃)
• zinc strip · oxidation
• copper strip · reduction
• Cell notation
• E°(cathode) − E°(anode) = +0.34 − (−0.76) = +1.10 V
• Electrons leave the zinc anode (oxidation, negative terminal) and flow through the external circuit to the copper cathode (reduction, positive terminal).
• The salt bridge (KNO₃ or KCl) keeps both solutions neutral: cations drift toward the cathode, anions toward the anode.
• Cell notation: anode on the left, cathode on the right; | is a phase boundary, ‖ the salt bridge.
• E°cell = E°(cathode) − E°(anode); E°cell > 0 and ΔG° = −nFE°cell < 0, so the cell reaction Zn + Cu²⁺ → Zn²⁺ + Cu is spontaneous.
• Every part of this figure is editable · sources on the template card

Drawn with 56 shapes – every one editable in MolDraw.

Sources

• Atkins, de Paula & Keeler, Atkins' Physical Chemistry, 11th ed., OUP 2018, ch. 6 Textbook
• Housecroft & Sharpe, Inorganic Chemistry, 5th ed., Pearson 2018, ch. 8 Textbook