Hanging mercury drop electrode
Encyclopedia
The hanging mercury drop electrode (HMDE) is a working electrode
variation on the dropping mercury electrode
(DME). Experiments run with dropping mercury electrodes are referred to as forms of polarography
. If the experiments are performed at an electrode with a constant surface (like the HMDE) it is referred as Voltammetry
.
Like other working electrodes these electrodes are used in electrochemical studies using three electrode systems
when investigating reaction mechanisms
related to redox
chemistry among other chemical
phenomenon.
drop of controlled geometry and surface area at the end of a capillary
in contrast to the dropping mercury electrode
(DME) which steadily releases drops of mercury during an experiments. The disadvantages a DME experiences due to a constantly changing surface are not experienced by the HMDE since it has static surface area during an experiment. The static surface of the HDME means it is more likely to suffer from the surface absorption phenomenon than a DME. Unlike solid electrodes which need to be cleaned and polished between most experiments, the self-renewing HMDE can simply release the contaminated drop and grow a clean drop between each experiment.
Working electrode
The working electrode is the electrode in an electrochemical system on which the reaction of interest is occurring. The working electrode is often used in conjunction with an auxiliary electrode, and a reference electrode in a three electrode system...
variation on the dropping mercury electrode
Dropping mercury electrode
The dropping mercury electrode is a working electrode made of mercury and used in polarography. Experiments run with mercury electrodes are referred to as forms of polarography even if the experiments are identical or very similar to a corresponding voltammetry experiment which use solid working...
(DME). Experiments run with dropping mercury electrodes are referred to as forms of polarography
Polarography
Polarography is a subclass of voltammetry where the working electrode is a dropping mercury electrode or a static mercury drop electrode ., useful for its wide cathodic range and renewable surface...
. If the experiments are performed at an electrode with a constant surface (like the HMDE) it is referred as Voltammetry
Voltammetry
Voltammetry is a category of electroanalytical methods used in analytical chemistry and various industrial processes. In voltammetry, information about an analyte is obtained by measuring the current as the potential is varied.- Three electrode system :...
.
Like other working electrodes these electrodes are used in electrochemical studies using three electrode systems
Potentiostat
A potentiostat is the electronic hardware required to control a three electrode cell and run most electroanalytical experiments. A Bipotentiostat and polypotentiostat are potentiostats capable of controlling two working electrodes and more than two working electrodes, respectively.The system...
when investigating reaction mechanisms
Electrochemical reaction mechanism
In chemistry, an electrochemical reaction mechanism is the step by step sequence of elementary steps, involving at least one outer sphere electron transfer, by which an overall chemical change occurs .- Overview :...
related to redox
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
chemistry among other chemical
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
phenomenon.
Distinction
The hanging mercury drop electrode (HDME) produces a partial mercuryMercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
drop of controlled geometry and surface area at the end of a capillary
Capillary
Capillaries are the smallest of a body's blood vessels and are parts of the microcirculation. They are only 1 cell thick. These microvessels, measuring 5-10 μm in diameter, connect arterioles and venules, and enable the exchange of water, oxygen, carbon dioxide, and many other nutrient and waste...
in contrast to the dropping mercury electrode
Dropping mercury electrode
The dropping mercury electrode is a working electrode made of mercury and used in polarography. Experiments run with mercury electrodes are referred to as forms of polarography even if the experiments are identical or very similar to a corresponding voltammetry experiment which use solid working...
(DME) which steadily releases drops of mercury during an experiments. The disadvantages a DME experiences due to a constantly changing surface are not experienced by the HMDE since it has static surface area during an experiment. The static surface of the HDME means it is more likely to suffer from the surface absorption phenomenon than a DME. Unlike solid electrodes which need to be cleaned and polished between most experiments, the self-renewing HMDE can simply release the contaminated drop and grow a clean drop between each experiment.