A modified version of Daniells Cells, a U—Shaped tube is replaced with a porous disk acting as saline bridge thus electric current is produced.

You need electrochemistry to understand oxidative metabolism.

Electrochemistry involves chemical processes in which the two sides of an oxidation-reduction reaction are separated in space. It is the study of chemical processes which electrons are caused to move. In an electrochemical cell, charges flow from the location of oxidation (anode) to the location of reduction (cathode). Electrochemistry is an important area of applied science. Galvanic and electrolytic cells are ubiquitous in the life science laboratory. Electrochemistry also provides a framework for describing a range of phenomena which occur in living systems the most prominent example being the electron transport system of mitochondria.

WikiPremed Resources

Redox Practice Items
Problem set for Oxidation-Reduction & Electrochemistry in PDF format

Answer Key
Answers and explanations

Electrochemistry Images
Image gallery for study with links to larger teaching JPEGs for classroom presentation

Question Drill for Electrochemistry
Conceptual Vocabulary Self-Test

Basic Terms Crossword Puzzle

Basic Puzzle Solution

Learning Goals


Be able to articulate the importance of the electroneutrality principle in governing electrochemical processes.

Understand what is meant by an electrode process.

Be able to name the components of a typical galvanic cell and describe its manner of operation.

Be able to describe the difference between a galvanic and electrolytic cell.

Be prepared to relate the current in an electrochemical cell to stoichiometrical quantities.

Comprehend the purpose of the salt bridge in an electrochemical cell.

Know what the difference is between the anode and the cathode and understand what their respective potentials will be in a galvanic or electrolytic cell.

Be able to conceptualize cell potentials and understand the electromotive or activity series of the metals.

Comprehend the meaning of a standard reduction potential.

Understand the relationship of cell potential and free energy change.

Understand the Nernst equation and how to work with it.

Be able to describe how the oxidation or reduction of water can be a competing process when an aqueous solution is subjected to electrolysis.

Suggested Assignments

Review terminology for electrochemistry using the question server. Complete the fundamental terms crossword puzzle. Here is the solution to the puzzle.

Perform the practice items for oxidation reduction and electrochemistry. Here is the answer key for the practice items.

Read pp. 197-202 in ExamKrackers Chemistry. Perform practice items 137-144 on pg 203.

Review the web resources for electrochemistry.

Conceptual Vocabulary for Electrochemistry

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.
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.
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.
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.
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.
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.
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.
Advanced terms that may appear in context in MCAT passages
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.
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.