Electrochemistry and Galvanic Cells

The difference in electrical potential between two electrodes in a galvanic cell, driving current from the electrode with higher reduction potential to the one with lower reduction potential.

The standard EMF of a cell when all reactants and products are in their standard states (1 atm pressure, 1 M concentration, 298 K).

A device that connects the two half-cells of a galvanic cell, allowing for the flow of ions without mixing the solutions.

An electrode where a metal is immersed in a solution containing its own ions.

An electrode made of an inert material like platinum, where a gas is bubbled through a solution containing its own ions.

An electrode consisting of a metal covered with a paste of its insoluble salt in contact with a solution containing a common ion.

An electrode where a platinum electrode is in contact with a redox system, involving the transfer of electrons.

The pressure at which gases involved in an electrode reaction should be kept.

A type of reference electrode where a mercury electrode is in contact with a paste of mercurous chloride (Hg2Cl2) and a saturated solution of KCl. Its potential is very stable and reproducible, making it suitable for measuring other electrode potentials.

An electrode where a silver wire coated with silver chloride is immersed in a solution of potassium chloride. It is a commonly used reference electrode in electrochemical measurements.

A standard hydrogen electrode (SHE) used as a reference point for measuring electrode potentials. The SHE is defined as having a standard electrode potential of 0.00V at 298K.

The potential difference between the two electrodes of an electrochemical cell, which drives the flow of electrons from the anode (oxidation) to the cathode (reduction).

The minimum voltage needed to initiate electrolysis and decompose a substance into its constituent elements.

The negative value of the change in free energy accompanying a redox reaction is equal to the electrical energy produced in a reversible cell.

The electrode with the more positive standard reduction potential will undergo reduction, while the electrode with the less positive standard reduction potential will undergo oxidation.

The potential difference between two half-reactions, representing the maximum electrical work that can be obtained from a reaction under standard conditions.

The process of using electrical energy to drive a non-spontaneous chemical reaction.

The reduction potential of an electrode at non-standard conditions, affected by the concentration of the electrolyte.

A measure of the tendency of a substance to gain electrons and undergo reduction, measured in volts.

When a metal is placed in a solution of its own salt, it can undergo oxidation (lose electrons) or reduction (gain electrons). The tendency for this process to happen is called electrode potential.

The electrode potential of a metal when measured against a standard hydrogen electrode (SHE) at a specific concentration (1 M) and temperature (25°C).

A type of electrode where the sensing part is made of a membrane that is selective to a specific ion. Examples include glass membranes for H+, Na+, or Ag+.

A stable and reproducible electrode with a fixed potential, used as a reference point to measure the potential of other electrodes. This helps ensure accurate measurements.

A layer formed at the interface between a metal electrode and its solution, consisting of a positive layer of metal ions and a negative layer of electrons. This layer determines the electrode potential.

The tendency of an electrode to lose electrons (give up electrons) when placed in a solution.

A measure of how easily electric current can flow through a material or solution.

The reciprocal of electrical resistance. It represents the ability of a material to conduct electricity.

The unit of conductance, measured in Siemens (S) or mho (ohm-1).

The conductance of one cubic centimeter (cm3) of a conductor or solution.

It's the reciprocal of specific resistance (ρ), representing the ease of electrical flow through a specific volume of material.

A constant that represents the ratio of the distance between two electrodes (l) to the area of the electrodes (a) in a conductivity cell.

A device used to measure the conductivity of a solution. It contains two electrodes with a fixed distance and area.

A process of determining the cell constant by measuring the conductivity of a solution with a known specific conductance, like 0.1M KCl solution at 298K.

A standard electrode with a potential of 0 volts, used to determine the standard electrode potential of other electrodes.

Hydrogen gas passed through the tube at 1 atm, a platinum foil attached at the end of the wire, and an electrode immersed in 1M H+ ion solution at 25°C.

The SHE acts as a cathode (reduction) when coupled with an electrode having a lower potential, and as an anode (oxidation) when coupled with an electrode having a higher potential.

The electrode potential of SHE is zero at all temperatures.

The process of determining the standard electrode potential of a specific electrode by comparing it to the SHE.

The tendency of a chemical species to gain electrons and become reduced.

A series of standard electrode potentials arranged in descending order. The most negative potential is at the top of the series.

SHE is difficult to set up and maintain, sensitive to poisoning, and not usable in solutions containing redox systems.