Electrolyte

As the electrolyte (from gr ἤλεκτρον electron, "Bernstein " i ü. S. " electric" and λυτικός lytikós, " solvable " ) refers to a chemical compound that is dissociated in the solid, liquid or dissolved state in which ions and directed under the influence of an electric field moves. It is often referred to as the electrolyte, the solid or liquid material, which contains the mobile ions. The electrical conductivity of such ion conductor is less than is typical of metals; they are therefore referred to as head of 2nd class.

Head first class ( with electrons as charge carriers ) in contact with an ionic conductor hot electrodes. Electrochemical reactions occur at the boundary surfaces, particularly in current flow.

Classification

Electrolytes are substances which are at least partly present as ions in the broadest sense. A distinction is made in

• Dissolved electrolytes strong electrolytes that are completely cleaved into ions when it is dissolved, such as saline.
• Weak electrolytes, which dissociate only partially in solution, such as acetic acid.

For conductivity of dissolved electrolytes see Electrolytic conductivity.

• Solid A real electrolyte is a substance consisting in the solid state of ionic crystals and melt or solution in special cases as a solid ( see Section solids), conducts electricity.

• A potential at the electrolyte, however, the ions are produced only by the reaction with the solvent.

Accordingly, the major electrolytes are either acids, bases or salts.

Liquids

Electrolytes in terms of ionic conductors require mobile ions. Thus, any liquids containing ions, electrolytes. Liquid electrolytes are both molten salts and ionic liquids as well as all liquid solutions of ions. Molten salts and ionic liquids consist normally of only ions, but they can contain dissolved molecules. For aqueous or organic electrolyte solutions, it is vice versa: Here is the solvent of molecules and ions are dissolved therein. The preparation of an electrolyte solution can consist in the simple dissolution of already existing ions, or in a chemical reaction, resulting from the ion, for example, an acid -base reaction as in the resolution of molecules such as hydrogen chloride or ammonia in water. Information about the translational mobility of ions in the electrolyte solution, such as the diffusion coefficient, or the mobility in the electric field can be obtained through field gradient NMR methods. However, the measure can also be done with the "classical " method of the "moving boundary " (moving boundary )

Solid

Even solids can contain mobile ions. Especially at high temperatures ions become mobile for example in existing ions from solids. There are also solid electrolytes, which can be used at room temperature or only slightly elevated temperatures. These include the polymer electrolyte membranes used in some fuel cells. They consist of a plastic skeleton, which contains ionic side groups. Important ion conductors such as some sodium aluminate. Besides the use in fuel cells, solid electrolytes are also important sensors, such as the lambda probe containing an electrolyte that conducts oxygen ions (eg, YSZ, yttria stabilized zirconia, a mixture of zirconium oxide and yttrium oxide Y2O3 ZrO2 ). The 1900 common than incandescent Nernst lamp used such solid electrolytes.

Biological electrolytes

The main biological ions electrolytes are sodium, potassium, calcium, magnesium, chloride, phosphate and hydrogen carbonate. They are contained in the cytosol and is indispensable for the function of the cells. Still other ions are trace elements necessary for the cell, but the ions mentioned particularly significant in view of the electrolyte balance of the cell, as they play a prominent role in the regulation of osmotic pressure.

Physiology

All higher forms of life maintain a subtle and complex electrolyte balance between their intracellular ( in their cells ) and extracellular upright (outside or between their cells ) environment. In particular, the maintenance of accurate osmotic gradient is important. These gradients affect and regulate the water balance of the body and the pH of the blood. Also for the function of nerve or muscle electrolytes play a central role. The regulation of the electrolyte concentration in the cell is effected by means of ion channels.

The electrolyte balance is maintained by oral administration and intestinal absorption of electrolyte-containing foods and substances, and is regulated by hormones. An excess is generally excreted through the kidney. In humans, homeostasis ( self-regulation ) of the salts by hormones such as antidiuretic hormone ( ADH), aldosterone and parathyroid hormone ( PTH) is controlled.

Causes of disturbances of electrolyte balance may be electrolyte losses (eg caused by diarrhea, vomiting) or disorders of endocrine glands. Severe electrolyte disturbances may lead to cardiac arrhythmias and nerve damage and are mostly medical emergencies.

It measures the electrolytes on blood and urine tests. The interpretation of these values ​​is difficult without considering the patient history and without the simultaneous investigation of renal function often impossible. The most widely studied electrolytes are sodium and potassium. The chloride level is rarely measured because it is associated with the sodium mirror.

Electrolyte-containing drinks with sodium and potassium salts are used to replenish electrolytes after dehydration. Causes is this fluid and electrolyte loss through profuse sweating so (physical work ), diarrhea, vomiting, excessive alcohol consumption or malnutrition. Pure distilled water is not helpful because it deprives the cells of the body salts and impairs their chemical functions. This can lead to overhydration.

Sports drinks contain electrolytes in addition to the large amounts of carbohydrates ( eg, glucose ) as energy donor. Due to the high sugar content, they are not suited to life for children. Even adult permanent users is recommended prevention of dental caries.

The over the counter drinks are usually isotonic, ie whose osmolarity is close to that of blood. Hypotonic (lower osmolarity ) and Hypertonic (higher osmolarity ) drinks are available for professional athletes, depending on their specific nutritional needs.

Electrolyte and sports drinks may also be prepared even with the correct proportions of sugar, salt and water.

Electrochemical applications

An important application is the use of the electrolyte in the electrolysis including electroplating. Electrolytes are also necessary components of batteries, accumulators and electrolytic capacitors. On the origin of the embossed by Michael Faraday term electrolyte See also " Faraday's law ", the importance of electrolyte concentration also see Nernst equation.

Galvanic electrolytes

In the following electroplating electrolytes are used.

• Aluminum electrolytes
• Antimony electrolytes
• Lead electrolytes
• Bronze electrolytes
• Cadmium electrolytes
• Cobalt electrolytes
• Chromium electrolytes
• Iron electrolytes
• Gold electrolytes
• Indiumelektrolyte
• Copper electrolyte
• Manga electrolytes
• Brass electrolytes
• Nickel electrolytes
• Nickel -iron- electrolytes
• Palladium electrolytes
• Platinum electrolytes
• Rheniumelektrolyte
• Rhodiumelektrolyte
• Rutheniumelektrolyte
• Silver electrolytes
• Bismuth electrolytes
• Tungsten electrolytes
• Zinc electrolytes
• Zinnelektrolyte