Electrochemistry Question Bank Review

Vocabulary flashcards covering the key terms, definitions, laws, and cell components found in the Electrochemistry Question Bank.

Molar Conductivity

The conducting power of all the ions produced by dissolving one mole of an electrolyte in a solution, commonly expressed with the units $\Omega^{-1}\,\text{cm}^2\,\text{mol}^{-1}$ or $\text{S}\,\text{cm}^2\,\text{mol}^{-1}$.

Resistivity

The electrical resistance offered by a conductor or electrolyte solution of unit length and unit cross-sectional area.

Cell Constant

The ratio of the distance between the two electrodes ($l$) to the cross-sectional area of the electrodes ($a$), having the SI unit $\text{m}^{-1}$ (or commonly $\text{cm}^{-1}$).

Reference Electrode

An electrode with a known, stable, and completely reproducible potential, used as a standard against which other electrode potentials are determined.

Standard Hydrogen Electrode (SHE)

The primary reference electrode against which all other standard electrode potentials are compared, assigned an arbitrary standard potential of $0.00\,\text{V}$ at all temperatures.

Salt Bridge

A U-shaped tube filled with an inert electrolyte in agar-agar gel that connects two half-cells, preventing liquid junction potential and maintaining electrical neutrality via ion flow.

Kohlrausch's Law of Independent Migration of Ions

A law stating that at infinite dilution, each ion contributes independently to the total molar conductivity of an electrolyte, irrespective of the nature of the other counterion.

Electrochemical Series

A series arranging standard redox couples in increasing or decreasing order of their standard reduction potentials ($E^\circ$).

$\text{H}_2\text{--}\text{O}_2$ Fuel Cell

A galvanic cell that directly transforms the chemical energy from the combustion of hydrogen and oxygen into electrical energy, famously utilized in the Apollo space program.

Leclanché Dry Cell

A primary commercial cell comprising a zinc anode, a graphite cathode surrounded by $\text{MnO}_2$ and carbon, and a moist paste electrolyte of $\text{NH}_4\text{Cl}$ and $\text{ZnCl}_2$.

Lead Accumulator

A secondary storage battery consisting of a spongy lead ($\text{Pb}$) anode, a lead dioxide ($\text{PbO}_2$) cathode, and dilute sulfuric acid ($\text{H}_2\text{SO}_4$) serving as the electrolyte.

NICAD Battery

A rechargeable secondary cell utilizing a cadmium ($\text{Cd}$) anode and a nickel(III) compound cathode in an alkaline medium.

Nernst Equation

An equation relating non-standard electrode or cell potential to the standard electrode potential, temperature, number of transferred electrons ($n$), and the reaction quotient ($Q$).

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

The potential difference of a galvanic cell when all reacting ions and solutes are at unit concentration ($1\,\text{M}$) and gases are at unit pressure ($1\,\text{atm}$ or $1\,\text{bar}$) at a specified temperature.

Cathodic Protection

An electrochemical method used to protect iron from rusting by coupling it to a more reactive sacrificial metal (such as zinc or magnesium) that undergoes oxidation preferentially.

Intensive Property of Cell Potential

A thermodynamic property where electrical potential ($E^\circ_{\text{cell}}$) does not depend on the size of the system or reaction stoichiometric coefficients, as derived from $\Delta G^\circ = -nFE^\circ_{\text{cell}}$.

Internal Circuit of a Galvanic Cell

The section of the electrochemical cell where the flow of current is sustained through the migration of cations and anions across solutions and through the salt bridge.

Platinum Foil in Hydrogen Electrode

A platinized platinum metal strip that provides an inert conducting surface for electron transfer and adsorbs hydrogen gas to facilitate equilibrium with $H^+\text{(aq)}$.