Electrochemistry and Galvanic Cells

Vocabulary flashcards covering electrochemistry, galvanic cells, cell potential calculations, free energy relationships, concentration cells, battery capacity, and modern 3D battery architectures.

Galvanic Cell

An electrochemical cell in which spontaneous reduction and oxidation reactions take place in separate locations to harness electron transfer and generate electricity.

Cathode

The electrode where reduction takes place (gaining electrons, $e^-$), corresponding to the half-reaction with the higher standard reduction potential ($E^\circ$).

Anode

The electrode where oxidation takes place (losing electrons, $e^-$), corresponding to the half-reaction with the lower standard reduction potential ($E^\circ$).

Salt Bridge

A U-tube containing an electrolyte solution (such as $\text{K}_2\text{SO}_4$ or $\text{KNO}_3$) that maintains electrical neutrality between two half-cells by allowing cations to flow toward the cathode and anions to flow toward the anode.

Standard Cell Potential Formula ($E^\circ_{\text{cell}}$)

The equation used to determine overall cell potential: $E^\circ_{\text{cell}} = E^\circ_{\text{red}} - E^\circ_{\text{ox}}$ (or $E^\circ_{\text{cell}} = E^\circ_{\text{cat}} - E^\circ_{\text{an}}$), where the minus sign automatically accounts for the reversed oxidation reaction.

Standard Free Energy Change ($\Delta G^\circ$)

A thermodynamic parameter calculated by $\Delta G^\circ = -nFE^\circ$, where a negative value indicates a spontaneous, product-favored process.

Faraday's Constant ($F$)

A constant value given as $96.5\,\text{kJ}/(\text{V}\times\text{mol }e^-)$, representing electric charge per mole of electrons.

Product-Favored Criteria

The thermodynamic conditions required for a spontaneous forward electrochemical reaction, defined by $E^\circ_{\text{cell}} > 0$ and/or $\Delta G^\circ < 0$.

Spectator Ions

Ions present in an electrochemical cell's electrolyte solution (such as $\text{SO}_4^{2-}$ or $\text{NO}_3^-$) that maintain charge balance without undergoing oxidation or reduction.

Concentration Cell

A galvanic cell in which both half-cells contain identical electrodes and chemical species ($E^\circ_{\text{cell}} = 0\,\text{V}$ under standard conditions), driven to produce voltage solely by a difference in ion concentrations until equilibrium is reached.

Battery "Death"

The termination of galvanic cell function occurring when at least one reactant electrode and/or reactant solution is depleted.

Battery Capacity

The total amount of work a battery can perform, which increases with a greater quantity of reactants ("more reactants, more work") even when different battery sizes (AAA, AA, C, D) share identical chemistry and voltage ($1.5\,\text{V}$).

3D Battery

An advanced architectural design with interdigitated cathode and anode structures surrounded by electrolyte, designed to charge faster and last longer.

Prof Amy Prieto

A researcher at Colorado State University noted for developing advanced 3D battery electrodes that charge faster and last longer.

Zinc-Copper Cell Reaction

The spontaneous galvanic reaction $\text{Zn}(s) + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu}(s)$ with $E^\circ_{\text{cell}} = +1.1\,\text{V}$ and $\Delta G^\circ = -212\,\text{kJ}$.

Lithium Cobalt Oxide Reaction

The spontaneous vehicle-powering reaction $\text{LiC}_6(s) + \text{CoO}_2(s) \rightarrow 6\text{C}(s) + \text{LiCoO}_2(s)$ with a calculated standard cell potential of $E^\circ_{\text{cell}} = +3.85\,\text{V}$.