"Large-scale production of chlorine involves several steps and many pieces of equipment. The description below is typical of a membrane plant. The plant also simultaneously produces sodium hydroxide (caustic soda) and hydrogen gas. A typical plant consists of brine production/treatment, cell operations, chlorine cooling & drying, chlorine compression & liquefaction, liquid chlorine storage & loading, caustic handling, evaporation, storage & loading and hydrogen handling. Key to the production of chlorine is the operation of the brine saturation/treatment system. Maintaining a properly saturated solution with the correct purity is vital, especially for membrane cells. Many plants have a salt pile which"
"electrons from the cathode and deposits on the cathode as sodium metal. NaCl dissolved in water can also be electrolyzed. The anode oxidizes chloride ions (Cl), and Cl gas is produced. However, at the cathode, instead of sodium ions being reduced to sodium metal, water molecules are reduced to hydroxide ions (OH) and hydrogen gas (H). The overall result of the electrolysis is the production of chlorine gas and aqueous sodium hydroxide (NaOH) solution. Commercially, electrolytic cells are used in electrorefining and electrowinning of several non-ferrous metals. Almost all high-purity aluminium, copper, zinc and lead is produced industrially in electrolytic"
"water, particularly when ions are added (salt water or acidic water), can be ""electrolyzed"" (subject to electrolysis). When driven by an external source of voltage, H ions flow to the cathode to combine with electrons to produce hydrogen gas in a reduction reaction. Likewise, OH ions flow to the anode to release electrons and an H ion to produce oxygen gas in an oxidation reaction. In molten sodium chloride, when a current is passed through the salt the anode oxidizes chloride ions (Cl) to chlorine gas, releasing electrons to the anode. Likewise the cathode reduces sodium ions (Na), which accept"
"the whole reaction continuing, and showing small resistance between the two electrodes. In this case, the two half-reactions are coupled together and limited by electron-transfer steps (electrolysis current saturated when further reducing the electrode distance). Two leads, running from the terminals of a battery, are placed in a cup of water with a quantity of electrolyte to establish conductivity in the solution. Using NaCl (table salt) in an electrolyte solution results in chlorine gas rather than oxygen due to a competing half-reaction. With the correct electrodes and correct electrolyte, such as baking soda (sodium bicarbonate), hydrogen and oxygen gases will"
"with chlorine gas in the presence of hydrochloric acid. Gold is dissolved at the anode, and pure gold, traveling through the acid by ion transfer, is plated onto the cathode. Silver forms an insoluble chloride slime and copper and platinum form soluble chlorides that are removed. This procedure is used on a very large industrial scale and has a large set up cost due to the amount of gold that needs to be permanently dissolved in the electrolyte. Electroparting is recent gold refining procedure where gold is separated from other metals in electrolytic cell in a way that dissolves all"
"(e.g. sulfate SO) oxygen is evolved at the anode. In both cases this is due to water being reduced to form hydrogen or oxidized to form oxygen. In principle the voltage required to electrolyze a salt solution can be derived from the standard electrode potential for the reactions at the anode and cathode. The standard electrode potential is directly related to the Gibbs free energy, ΔG, for the reactions at each electrode and refers to an electrode with no current flowing. An extract from the table of standard electrode potentials is shown below. In terms of electrolysis, this table should"
"to a partial hydrate of magnesium chloride by treating the hydroxide with hydrochloric acid and heating of the product: The salt is then electrolyzed in the molten state. At the cathode, the ion is reduced by two electrons to magnesium metal: At the anode, each pair of ions is oxidized to chlorine gas, releasing two electrons to complete the circuit: A new process, solid oxide membrane technology, involves the electrolytic reduction of MgO. At the cathode, ion is reduced by two electrons to magnesium metal. The electrolyte is yttria-stabilized zirconia (YSZ). The anode is a liquid metal. At the YSZ/liquid"
"Electride An electride is a ionic compound in which an electron is the anion. Solutions of alkali metals in ammonia are electride salts. In the case of sodium, these blue solutions consist of [Na(NH)] and solvated electrons: The cation [Na(NH)] is an octahedral coordination complex. Addition of a complexant like crown ether or 2,2,2-cryptand to a solution of [Na(NH)]e affords [Na(crown ether)]e or [Na(2,2,2-crypt)]e. Evaporation of these solutions yields a blue-black paramagnetic salt with the formula [Na(2,2,2-crypt)]e. Most solid electride salts decompose above 240 K, although [CaAlO](e) is stable at room temperature. In these salts, the electron is delocalized between"
"in respect to its reduction and oxidation in both electrodes. Usually, water is electrolysed as mentioned in electrolysis of water yielding ""gaseous oxygen in the anode"" and gaseous hydrogen in the cathode. On the other hand, sodium chloride in water dissociates in Na and Cl ions, cation, which is the positive ion, will be attracted to the cathode (-), thus reducing the sodium ion. The anion will then be attracted to the anode (+) oxidizing chloride ion. The following half reactions describes the process mentioned: Reaction 1 is discarded as it has the most negative value on standard reduction potential"
"electrolyte, turning them into molecules of hydrogen gas that bubble up around the electrode. The zinc ion combines with the sulfate ion to form zinc sulfate, and this salt falls to the bottom of the cell. The effect of all this is that the dissolving zinc electrode becomes negatively charged, the copper electrode is left with a positive charge and electrons from the zinc pass through the external circuit to the copper electrode. The molecules of some crystals and ceramics are permanently polarised: some parts of the molecule are positively charged, while other parts are negatively charged. These materials produce"
"and copper electrode are placed in a dilute solution of sulfuric acid, the two metals react to each other's presence within the electrolyte and develop a potential difference of about 1 volt between them. When a conducting path joins the electrodes externally, the zinc electrode dissolves slowly into the acid electrolyte, The zinc molecule goes into the electrolyte in the form of positive ions while its electrons are left on the electrode. The copper electrode on the other hand does not dissolve in the electrolyte. Instead it gives up its electrons to the positively charged ions of hydrogen in the"
"or more of its electrons, becoming a positively charged cation, and the electrons are then gained by the non-metal atom, becoming a negatively charged anion. The two oppositely charged ions attract one another, and the ionic bond is the electrostatic force of attraction between them. For example, sodium (Na), a metal, loses one electron to become an Na cation while chlorine (Cl), a non-metal, gains this electron to become Cl. The ions are held together due to electrostatic attraction, and that compound sodium chloride (NaCl), or common table salt, is formed. In a covalent bond, one or more pairs of"
"neck (B) and liquid in the body of the vessel. Sodium metal forms at the cathode but is less dense than the fused sodium hydroxide electrolyte. Wire gauze (G) confines the sodium metal to accumulating at the top of the collection device (P). The cathode reaction is The anode reaction is Despite the elevated temperature, some of the water produced remains dissolved in the electrolyte. This water diffuses throughout the electrolyte and results in the reverse reaction taking place on the electrolized sodium metal: with the hydrogen gas also accumulating at (P). This, of course, reduces the efficiency of the"
"electrolyte is the solution of same substances but with different concentration. Electrode Concentration cell - In this type of cell two electrodes of same substance but with different concentration are dipped in same solution. In the presence of water, a high concentration of metal ions will exist under faying surfaces and a low concentration of metal ions will exist adjacent to the crevice created by the faying surfaces. An electrical potential will exist between the two points. The area of the metal in contact with the high concentration of metal ions will be cathodic and will be protected, and the"
"to the emission of toxic chlorine gas, and the prevalence of the more general chloralkali process, the electrolysis will convert the copper metal to copper ions in solution forming the compound. Indeed, any solution of copper ions can be mixed with hydrochloric acid and made into copper chloride by removing any other ions. Copper(II) chloride occurs naturally as the very rare anhydrous mineral tolbachite and the dihydrate eriochalcite. Both are found near fumaroles. More common are mixed oxyhydroxide-chlorides like atacamite Cu(OH)Cl, arising among Cu ore beds oxidation zones in arid climate (also known from some altered slags). A major industrial"
"Chloride The chloride ion is the anion (negatively charged ion) Cl. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts such as sodium chloride are often very soluble in water. It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating fluid in and out of cells. Less frequently, the word ""chloride"" may also form part of the ""common"" name of chemical compounds in which one or more chlorine atoms"
"all the chlorine is in fact the hydrochloric acid, with the salt acting as a non-consumed intermediary, being split and reformed. The whole process is exactly balanced by equivalents: the amount of chlorine produced is directly related to the amount of hydrochloric acid used, other things remaining equal. This could be represented roughly as follows (with the ions all separated in solution): Use of another acid, such as sulphuric acid to neutralise pool alkalinity will reduce the pH but will produce sulphate ions rather than chloride ions. Sulphate ions conduct electricity equally well as chloride at the electrode, but will"
"and an anode). The electrolyte is usually a solution of water or other solvents in which ions are dissolved. Molten salts such as sodium chloride are also electrolytes. When driven by an external voltage applied to the electrodes, the ions in the electrolyte are attracted to an electrode with the opposite charge, where charge-transferring (also called faradaic or redox) reactions can take place. Only with an external electrical potential (i.e. voltage) of correct polarity and sufficient magnitude can an electrolytic cell decompose a normally stable, or inert chemical compound in the solution. The electrical energy provided can produce a chemical"
"the cathode and anode in the electrolyte. However, electrolysis requires an external source of electrical energy to induce a chemical reaction, and this process takes place in a compartment called an electrolytic cell. When molten, the salt sodium chloride can be electrolyzed to yield metallic sodium and gaseous chlorine. Industrially this process takes place in a special cell named Down's cell. The cell is connected to an electrical power supply, allowing electrons to migrate from the power supply to the electrolytic cell. Reactions that take place at Down's cell are the following: This process can yield large amounts of metallic"
"in ammonia and amines are the anions of salts called electrides. Such salts can be isolated by the addition of macrocyclic ligands such as crown ether and cryptands. These ligands bind strongly the cations and prevent their re-reduction by the electron. Its standard electrode potential value is -2.77 V. Equivalent conductivity 177 Mho cm is similar to that of hydroxide ion. This value of equivalent conductivity corresponds to a diffusivity of 4,75*10 cms. Some thermodynamic properties of the solvated electron have been investigated by Jortner and Noyes (1966) Alkaline aqueous solutions above pH = 9.6 regenerate the hydrated electron through"
"of chlorine and caustic soda. This is a prime example of a competing side reaction. The electrolysis of brine, a water/sodium chloride mixture, is only half the electrolysis of water since the chloride ions are oxidized to chlorine rather than water being oxidized to oxygen. Thermodynamically, this would not be expected since the oxidation potential of the chloride ion is less than that of water, but the rate of the chloride reaction is much greater than that of water, causing it to predominate. The hydrogen produced from this process is either burned (converting it back to water), used for the"
"higher resistance. The same current would, however, flow through all the electrodes. On the other hand, in parallel or bipolar arrangement the electric current is divided between all the electrodes in relation to the resistance of the individual cells, and each face on the electrode has a different polarity. During electrolysis, the positive side undergoes anodic reactions, while on the negative side, cathodic reactions are encountered. Consumable metal plates, such as iron or aluminum, are usually used as sacrificial electrodes to continuously produce ions in the water. The released ions neutralize the charges of the particles and thereby initiate coagulation."
"even more simple terms a simple ionic compound (with positive and negative ions) such as sodium chloride (common salt) is easily soluble in a highly polar solvent (with some separation of positive (δ+) and negative (δ-) charges in the covalent molecule) such as water, as thus the sea is salty as it accumulates dissolved salts since early geological ages. The solubility is favored by entropy of mixing (Δ""S"") and depends on enthalpy of dissolution (Δ""H"") and the hydrophobic effect. The free energy of dissolution (Gibbs energy) depends on temperature and is given by the relationship: Δ""G"" = Δ""H"" – TΔ""S""."
"of electrochemical engineering. The most common chloralkali process involves the electrolysis of aqueous sodium chloride (a brine) in a membrane cell. Saturated brine is passed into the first chamber of the cell where the chloride ions are oxidised at the anode, losing electrons to become chlorine gas (A in figure): At the cathode, positive hydrogen ions pulled from water molecules are reduced by the electrons provided by the electrolytic current, to hydrogen gas, releasing hydroxide ions into the solution (C in figure): The ion-permeable ion exchange membrane at the center of the cell allows the sodium ions (Na) to pass"
"KCl electrolyte solution increases the reference potential to +0.238 V vs. SHE at 25 °C, and a 0.1 M solution to +0.3356 V at the same temperature. The SCE is used in pH measurement, cyclic voltammetry and general aqueous electrochemistry. This electrode and the silver/silver chloride reference electrode work in the same way. In both electrodes, the activity of the metal ion is fixed by the solubility of the metal salt. The calomel electrode contains mercury, which poses much greater health hazards than the silver metal used in the Ag/AgCl electrode. Saturated calomel electrode The Saturated calomel electrode (SCE) is"
"a variety of forms. For example, in a crystal of sodium chloride (common salt), the crystal is made up of ionic sodium and chlorine, and held together with ionic bonds. In others, the atoms share electrons and form covalent bonds. In metals, electrons are shared amongst the whole crystal in metallic bonding. Finally, the noble gases do not undergo any of these types of bonding. In solid form, the noble gases are held together with van der Waals forces resulting from the polarisation of the electronic charge cloud on each atom. The differences between the types of solid result from"
"cathode (positive part of the cell) and the fluoride ions remain in solution. After electrolysis, potassium fluoride remains in solution. The modern version of the process uses steel containers as cathodes, while blocks of carbon are used as anodes. The carbon electrodes are similar to those used in the electrolysis of aluminium. An earlier version of fluorine production process, by Moissan, uses platinum group metal electrodes and carved fluorite containers. The voltage for the electrolysis is between 8 and 12 volts. Pure fluorine gas may be stored in steel cylinders where the inside surface is passivated by a metal fluoride"
"a cathode, the other is an anode. As the water flows through the anode/cathode channel, a low voltage DC current's applied. When this happens, the electrolysis is triggered and sodium hypochlorite is instantly produced as well as hydrogen gas (H). The hydrogen rich sodium hypochlorite then travels to a tank that removes the hydrogen gas. The dehydrogenization mechanism varies from device to device but the process is generally the same. After hydrogen has been removed from the solution, it is stored in a tank as the finished product. No chemicals other than ordinary salt, or sodium chloride (NaCl), are used"
"to the evolution of hydrogen gas from the copper or silver electrode. The modern, atomic understanding of a cell with zinc and copper electrodes separated by an electrolyte is the following. When the cell is providing an electrical current through an external circuit, the metallic zinc at the surface of the zinc anode is oxidised and dissolves into the electrolyte as electrically charged ions (Zn), leaving 2 negatively charged electrons () behind in the metal: This reaction is called oxidation. While zinc is entering the electrolyte, two positively charged hydrogen ions (H) from the electrolyte accept two electrons at the"
"Columbus, Mississippi, United States was never completed. Two different salt solution electrolytes are contained in two separate tanks. When energy is required, a solution of NaS (sodium disulfide) is pumped to the anode, and NaBr (sodium tribromide) is pumped to the cathode. The anode and cathode, and their corresponding salt solutions, are separated by an ion exchange membrane. At the negative electrode, the anodic reaction is shown as: 2NaS → NaS + 2Na + 2e At the positive electrode, the cathodic reaction is shown as: NaBr + 2Na + 2e→ 3NaBr As energy is drawn from the system, the sodium"
"oxygen gas will be produced. A cation with a greater standard electrode potential than a hydrogen ion will be reduced instead, and no hydrogen gas will be produced. The following cations have lower electrode potential than H and are therefore suitable for use as electrolyte cations: Li, Rb, K, Cs, Ba, Sr, Ca, Na, and Mg. Sodium and lithium are frequently used, as they form inexpensive, soluble salts. If an acid is used as the electrolyte, the cation is H, and there is no competitor for the H created by disassociating water. The most commonly used anion is sulfate (),"
"The electrolyte is normally a custom solution of sodium carbonate (soda ash) mixed on-site for the specific job. This salt is alkaline and electrode corrosion effects on galvanised steel tanks is manageable if re-galvanisation is possible. The resistance of the bulk electrolyte is a function of temperature and the concentration of the salt governed by the formula: where ""θ"" is the temperature (in Celsius) and ""R"" is the standardised or datum calibration temperature. A specialised technique is required to accurately calibrate an LNER electrolyte bulk resistance value and it is normally carried out by experienced power engineers and technicians. This"
"the cations. Electrides are paramagnetic and Mott insulators. Properties of these salts have been analyzed. Solutions of electride salts are powerful reducing agents, as demonstrated by their use in the Birch reduction. Evaporation of these blue solutions affords a mirror of Na. Such solutions slowly lose their colour as the electrons reduce ammonia: This conversion is catalyzed by various metals. An electride, [Na(NH)]e, is formed as a reaction intermediate. Theoretical evidence supports electride behaviour in insulating high-pressure forms of potassium, sodium, and lithium. Here the isolated electron is stabilized by efficient packing, which reduces enthalpy under external pressure. The electride"