Oxidation-Reduction and Electrochemistry

Each list begins with basic conceptual vocabulary you need to know for MCAT questions and proceeds to advanced terms that might appear in context in MCAT passages. The terms are links to Wikipedia articles.
Redox, shorthand for reduction/oxidation reaction, is a term used to describe chemical reactions in which atoms have their oxidation state changed.
Oxidizing agent
An oxidizing agent is a substance that gains electrons in a redox chemical reaction.
Reducing agent
A reducing agent is the element or a compound that reduces another species in a redox reaction. It is the electron donor in the redox.
Electrochemistry is a branch of chemistry that studies the reactions which take place at the interface of an electronic conductor and an ionic conductor.
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit.
Galvanic cell
A galvanic cell (or voltaic cell) consists of two different metals connected by a salt bridge or a porous disk between the individual half-cells.
Electrolytic cell
Electrolytic cells are composed of a vessel used to perform electrolysis and a cathode and anode.
Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames.
Potassium permanganate contains manganese bonded to four oxygens. Often employed for laboratory redox, it is a strong oxidizer with manganese in the +7 oxidation state.
Lithium aluminium hydride
Lithium aluminium hydride is a powerful reducing agent used in organic chemistry.
Oxidation number
Within a molecule or complex, the oxidation number of an element is the charge that it would have if the compound were composed of ions, with assignment of shared electrons based on electronegativity.
Oxidation state
The oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. It is usually numerically equal to the oxidation number.
Electrochemical cell
An electrochemical cell is a device used for creating an electromotive force and current from chemical reactions.
An electrolyte is a substance containing free ions that behaves as an electrically conductive medium.
Electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them.
Sodium borohydride
Prepared by the reaction of sodium hydride on trimethylborate, sodium borohydride is a reducing agent often used to reduce aldehydes and ketones into alcohols.
Hydride is the name given to the negative ion of hydrogen. Although this ion does not exist except in extraordinary conditions, the term is widely applied to describe compounds of hydrogen with other elements.
An important group of oxidizing agents, the chromates are salts of chromic acid.
A half reaction is either the oxidation or reduction reaction component of a redox reaction.
Reduction potential
Standard reduction potential is the tendency of a chemical species to acquire electrons and thereby be reduced.
Electromotive force
Electromotive force or potential of a body is the work done in joules to bring a unit electric charge from infinity to the body.
An anode is an electrode through which the positive direction of electric current flows into a polarized electrical device.
A cathode is an electrode through which the positive direction of electric current flows out of a polarized electrical device.
Hydroboration-oxidation reaction
Employing borane in tetrahydrofuran in the first step, the hydroboration-oxidation reaction is a two-step organic chemical reaction that converts an alkene into a neutral alcohol by the net addition of water across the double bond.
Hydrogenation is a class of chemical reactions which result in an addition of hydrogen molecule usually to unsaturated organic compounds.
Oxidative addition
Oxidative addition is an important classes of reactions in organometallic chemistry in which a metal complex with vacant coordination sites and a relatively low oxidation state is oxidized by the insertion into a covalent bond.
Electron transfer
Electron transfer is the process by which an electron moves from one atom or molecule to another atom or molecule.
Electron acceptor
A terminal electron acceptor is a compound that receives or accepts an electron during cellular respiration or photosynthesis.
Electron donor
In general terms, an electron donor gives up an electron during cellular respiration.
Salt bridge
A salt bridge is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic cell.
Standard electrode potential
The standard electrode potential is the measure of individual voltage of any electrode at standard ambient conditions, which is at a temperature of 298K, solutes at a concentration of 1 M, and gases at a pressure of 1 bar.
Nernst equation
The Nernst equation gives the electrode potential relative to the standard electrode potential of the electrode couple as a function of component concentrations.
Reductive elimination
The reverse of oxidative addition is reductive elimination.
Tollens reagent
Tollens' reagent is usually ammoniacal silver nitrate, an oxidizing agent, which is itself reduced to silver metal. It is used as a test for aldehydes.
Manganese(IV) oxide is the chemical compound in which manganese is bound to two oxygens. It is often used to oxidize allylic alcohols to the corresponding aldehydes.
Superoxide is the free radical product of the one-electron reduction of dioxygen.
A peroxide is a compound containing an oxygen-oxygen single bond.
Metathesis reaction
Metathesis is a bimolecular process involving the exchange of bonds between the two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations.
Standard hydrogen electrode
The standard hydrogen electrode is a redox electrode which forms the basis of the thermodynamic scale of oxidation-reduction potentials.
Faraday constant
The Faraday constant is the amount of electric charge in one mole of electrons.
Electroplating is the process of using electrical current to coat an electrically conductive object with a relatively thin layer of metal.
Half cell
A half cell is a structure that contains a conductive electrode and a surrounding conductive electrolyte separated by a naturally-occurring Helmholtz double layer.
Lindlar catalyst
Used for the hydrogenation of alkynes to alkenes, Lindlar catalyst is a heterogeneous catalyst that consists of palladium deposited on calcium carbonate and treated with various forms of lead.
Ozonolysis is the cleavage of an alkene or alkyne with ozone to form compounds in which the multiple carbon-carbon bond has been replaced by a double bond to oxygen.
Hydrogenolysis is a catalytic chemical reaction whereby a molecule of hydrogen is added over a carbon-heteroatom single bond, effectively causing a lysis of the bond.
Denitrification is the process of reducing nitrate and nitrite, which can be thought of as the opposite of nitrogen fixation
An oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another.
Palladium-Hydrogen electrode
The Palladium-Hydrogen electrode is one of the common reference electrodes used in electrochemical study.
Reference electrode
A reference electrode is an electrode which has a stable and well-known electrode potential.
Concentration cell
A concentration cell is an electrochemical cell that has two equivalent half-cells of the same material differing only in molarity.
Primary cell
A primary cell is any kind of electrochemical cell in which the electrochemical reaction of interest is not reversible.
Rechargeable battery
A rechargeable battery, also known as a storage battery, is a group of two or more secondary cells.
Wolff-Kishner reduction
The Wolff-Kishner reduction is a chemical reaction that fully reduces a ketone (or aldehyde) to an alkane.
Jones oxidation
The Jones oxidation is a chemical reaction described as the chromic acid oxidation of primary and secondary alcohols to carboxylic acids and ketones, respectively.
Clemmensen reduction
The Clemmensen reduction is a chemical reaction described as a reduction of ketones or aldehydes to alkanes using zinc amalgam and hydrochloric acid.
Inner sphere electron transfer
Inner sphere electron transfer proceeds via a covalent linkage between the two redox partners, the oxidant and the reductant.
Outersphere electron transfer
Outer sphere electron transfer refers to an electron transfer event that occurs between chemicals that remain separate species before, during, and after the electron transfer event.
Voltaic pile
The voltaic pile is the first modern electric battery, invented by Alessandro Volta in 1800.
Electroanalytical methods
Electroanalytical chemistry involves the analysis of chemical species through the use of electrochemical methods.
Galvanic series
The galvanic series determines the nobility of metals and semi-metals by submerging two metals in an electrolyte, while electrically connected, and determining the less noble as the one that experiences corrosion.
Anodizing is an electrolytic passivation process used to increase the thickness and density of the natural oxide layer on the surface of metal parts.
Lead-acid battery
Lead-acid batteries are the oldest type of rechargeable battery.
One-electron reduction
A one-electron reduction in organic chemistry involves the transfer of an electron from a metal to an organic substrate.
Pyridinium chlorochromate
Pyridinium chlorochromate is a reddish orange solid reagent used to oxidize primary alcohols to aldehydes and secondary alcohols to ketones.
Collins Reagent
Collins reagent is the complex of chromium(VI) oxide with pyridine in dichloromethane. It is used to selectively oxidize primary alcohols to the aldehyde, and will tolerate many other functional groups within the molecule.
Peroxy acid
A peroxy acid is an acid in which an acidic -OH group has been replaced by an -OOH group.
Raney nickel
Raney nickel is a solid catalyst composed of fine grains of a nickel-aluminium alloy, used in many industrial processes, most commonly for hydrogenation reactions.
Osmium tetroxide
Osmium tetroxide is the chemical compound with one oxmium atom bonded to four oxygens. It is an important oxidizing agent in the laboratory.
Perchlorates are the salts derived from perchloric acid, which are important oxidizing agents for their tendency not to react unless heated.
Electrowinning, also called electroextraction, is the electrodeposition of metals from their ores that have been put in solution or liquefied.
Cyclic voltammetry
Cyclic voltammetry is a type of potentiodynamic electrochemical measurement in which a voltage is applied to a working electrode in solution and current flowing at the working electrode is plotted versus the applied voltage.
Voltammetry is a category of electroanalytical methods used in analytical chemistry and various industrial processes in which information about an analyte is obtained by measuring the current as the potential is varied.
Copper coulometer
Measuring a quantity of electricity by mass change of the electrodes, the copper coulometer consists of two identical copper electrodes immersed into the slightly acidic pH-buffered solution of copper sulfate.
Redox electrode
A redox electrode is an electrode made from electron-conductive material and characterized by high chemical stability in the solution under test.
Rosenmund reduction
The Rosenmund reduction is a chemical reaction that reduces an acid halide to an aldehyde using hydrogen gas over palladium-on-carbon poisoned with barium sulfate.
Cannizzaro reaction
The Cannizzaro reaction is a chemical reaction that involves the base-induced disproportionation of an aldehyde lacking a hydrogen atom in the alpha position.
Fremy's salt
Fremy's salt is a chemical compound and a strong oxidizing agent. The formal name is disodium nitrosodisulfonic acid the name refers equally well to the potassium salt potassium nitrosodisulfonate.
Swern oxidation
The mild Swern oxidation is a chemical reaction whereby a primary or secondary alcohol is oxidized to an aldehyde or ketone using oxalyl chloride, dimethyl sulfoxide and an organic base, such as triethylamine.
Corey-Kim oxidation
The Corey-Kim oxidation is an oxidation reaction used to synthesise aldehydes and ketones from primary and secondary alcohol
Redox signaling
Redox signaling is the concept that free radicals, reactive oxygen species, and other electronically-activated species act as messengers in biological systems.
Marcus theory
Marcus Theory was originally developed to explain outer sphere electron transfer, but was later extended to inner sphere electron transfer by Noel Hush.
Dry pile
The Dry-Pile (also known as the Duluc pile or Zamboni pile) is a high voltage low current semi-permanent electric battery developed in the early 1800s and constructed from silver foil, zinc foil, and paper.
Saturated calomel electrode
The saturated calomel electrode is a reference electrode based on the reaction between elemental mercury and mercury chloride.
Silver chloride electrode
A silver chloride electrode is a type of reference electrode, used for measuring electrochemical potential, which is the most commonly used reference electrode for testing cathodic protection corrosion control systems in sea water environments.
Cathodic protection
Cathodic protection is a technique to control the corrosion of a metal surface by making that surface the cathode of an electrochemical cell.
Differential pulse voltammetry
Differential pulse voltammetry is a kind of electrochemical measurement which can be considered as a series of regular voltage pulses superimposed on a linearly changing voltage, in which the resulting current is measured between the ramped baseline voltage and the pulse voltage.
Chronoamperometry is an electrochemical technique in which the potential of the working electrode is stepped, and the resulting current from faradaic processes occurring at the electrode is monitored as a function of time.
Cottrell equation
The Cottrell equation describes the change in electric current with respect to time in a controlled potential experiment, such as chronoamperometry.
Betts electrolytic process
The Betts electrolytic process is an industrial process for separating lead and bismuth.
Castner Process
The Castner process is a process for manufacturing sodium metal by electrolysis of molten sodium hydroxide.
Castner-Kellner process
The Castner-Kellner process is a method of electrolysis on an aqueous alkali chloride solution to produce the corresponding alkali hydroxide.
Chloralkali process
A chloralkali process is any electrolytic process which produces chlorine or a related oxidizer, such as bleaching powder, and an alkaline salt such as sodium hydroxide or sodium carbonate.
Meerwein-Ponndorf-Verley reduction
The Meerwein-Ponndorf-Verley-Reduction in organic chemistry is the reduction of ketones to secondary alcohols with aluminumisopropylate catalysis in isopropanol solution.
Oppenauer oxidation
Oppenauer oxidation is a gentle method for oxidizing secondary alcohols to ketones. The reaction is the opposite of Meerwein-Ponndorf-Verley reduction.
Kornblum oxidation
The Kornblum oxidation is a chemical reaction of a primary halide with dimethyl sulfoxide (DMSO) to form an aldehyde.
IBX acid
IBX acid or 2-Iodoxybenzoic acid is an organic compound used in organic chemistry as an oxidizing agent, especially to oxidize alcohols to aldehydes.
Dess-Martin periodinane
Dess-Martin periodinane is an chemical reagent with multiple advantages used to oxidize primary alcohols to aldehydes and secondary alcohols to ketones.
Birch reduction
The Birch reduction is the organic reduction of aromatic rings with sodium in liquid ammonia to form 1,4-cyclohexadienes.
McMurry reaction
The McMurry reaction is an organic reaction in which two ketone or aldehyde groups are coupled to an alkene in the presence of a titanium chloride compound such as titanium(III) chloride and a reducing agent.

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