What is the free radical property of ClO2?
The "free radical" property of ClO2 makes it particularly useful for addressing structural microbial contamination problems. Liquid ClO2 solution can be applied directly to known areas of microbial contamination, or entire contaminated structures can be fumigated with the gas by simply stripping it back out of solution at the point of application.
Is ClO2 a carcinogen?
Since ClO2 is an oxidative biocide, microorganisms cannot build up a resistance to it. Unlike chlorine, chlorine dioxide is not a chlorinating agent and pure chlorine dioxide does not form trihalomethanes (THMs), an environmental pollutant that is considered carcinogenic.
How does ClO2 decompose?
Any ClO 2 that is applied as part of either a liquid or gaseous treatment decays quickly to harmless concentrations of various sodium salts including chlorite, chlorate, and chloride. ClO 2 is a small, volatile, and very strong molecule that reacts with other substances by way of oxidation rather than by substitution (i.e. chlorination).
Is ClO2 a better oxidising agent than chlorine?
Chlorine and chlorine dioxide are both oxidising agents (electron receivers). However, chlorine has the capacity to take in two electrons, whereas chlorine dioxide can absorb five. This means that, mole for mole, ClO 2 is 2.6 times more effective than chlorine.
Preparation
Handling properties
Uses
How to avoid free radicals?
What are some examples of free radicals?
What is a molecule with one or more unpaired electrons called?
What are radicals in biology?
What is the difference between a neutral radical and an anion?
Is chlorine dioxide a free radical?
Is a basic radical an ion?
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Is cl2o a free radical?
Chlorine dioxide is a small, volatile and very strong molecule. In diluted, watery solutions chlorine dioxide is a free radical. At high concentrations it reacts strongly with reducing agents. Chlorine dioxide is an unstable gas that dissociates into chlorine gas (Cl2), oxygen gas (O2) and heat.
What type of compound is ClO2?
Chlorine dioxide (ClO2) is a chemical compound consisting of one chlorine atom and two oxygen atoms. It is a reddish to yellowish-green gas at room temperature that dissolves in water. It is used for a variety of antimicrobial uses, including the disinfection of drinking water.
What is the structure of ClO2?
The molecule ClO2 has an odd number of valence electrons, and therefore, it is a paramagnetic radical. In 1933, Lawrence O. Brockway, a graduate student of Linus Pauling, proposed a structure that involved a three-electron bond and two single bonds.
Why is ClO2 highly reactive?
Because of its radical structure, Chlorine Dioxide has a particular reactivity - totally different from that of chlorine or ozone.
What is ClO2 called?
Chlorine dioxide is a gas.
Which of the following is true about ClO2?
1 Answer. The correct option is (a) It is paramagnetic. Explanation: ClO2 molecule has an angular structure with O-CI-O bond angle of 117.6o.
Why does ClO2 violate the octet rule?
Although they are few, some stable compounds have an odd number of electrons in their valence shells. With an odd number of electrons, at least one atom in the molecule will have to violate the octet rule. Examples of stable odd-electron molecules are NO, NO 2, and ClO 2.
Is ClO2 planar?
The valence shell electron pair repulsion theory is as follows: Electron pair is the number of electron pairs present around the central atom in a molecule....Shape of ClO−2 ion is: A. Linear. B. Angular. C. Pyramidal. D. None of the above.Number of electron pairGeometry$2$Linear$3$Trigonal planar$4$Tetrahedral2 more rows
Does ClO2 obey octet rule?
Lewis Dot of the Chlorite Ion ClO2- In this ion, the chlorine atom does follow the octet rule, unlike ClO3−, or ClO4−.
Is ClO2 polar or nonpolar?
Definitely ClO2- is polar in nature as it lacks symmetry because it has a molecular geometry of bent, which means dipole generated along with Cl-O bond unable to canceled out each other giving some dipole moment in the molecule.
Is ClO2 an acid or base?
Chlorite is a chlorine oxoanion and a monovalent inorganic anion. It is a conjugate base of a chlorous acid....7.3Evaluations of the Joint FAO/WHO Expert Committee on Food Additives - JECFA.Chemical NameCHLORITEEvaluation Year20074 more rows
Which of the following do represent the characteristics of ClO2?
(C) ClO2 is sp3. d hybridized (D) All of the above. It is an odd electron molecule so option A is correct. It does not form dimer as odd electron is delocalised so forms two centre three electron bond.
What is the advantage of not using chloride based processes?
Two advantages of not using the chloride-based processes are that there is no formation of elemental chlorine, and that sodium sulfate, a valuable chemical for the pulp mill, is a side-product.
What are the dangers of chlorine dioxide?
Potential hazards with chlorine dioxide include health concerns, explosiveness and fire ignition. It is commonly used as a bleach . Chlorine dioxide was discovered in 1811 by Sir Humphry Davy and has been widely used for bleaching purposes in the paper industry, and for treatment of drinking water.
When was chlorine dioxide first used?
The Niagara Falls, New York, water treatment plant first used chlorine dioxide for drinking water treatment in 1944 for destroying "taste and odor producing phenolic compounds ". Chlorine dioxide was introduced as a drinking water disinfectant on a large scale in 1956, when Brussels, Belgium, changed from chlorine to chlorine dioxide. Its most common use in water treatment is as a pre- oxidant prior to chlorination of drinking water to destroy natural water impurities that would otherwise produce trihalomethanes on exposure to free chlorine. Trihalomethanes are suspect carcinogenic disinfection by-products associated with chlorination of naturally occurring organics in the raw water. Chlorine dioxide is also superior to chlorine when operating above pH 7, in the presence of ammonia and amines and for the control of biofilms in water distribution systems. Chlorine dioxide is used in many industrial water treatment applications as a biocide including cooling towers, process water, and food processing.
Is chlorine dioxide a miracle mineral?
See also: Miracle Mineral Supplement. Chlorine dioxide is fraudulently marketed as a magic cure for a range of diseases from Brain cancer to HIV/AIDS. Enemas of chlorine dioxide are a supposed cure for childhood autism, resulting in complaints to the FDA reporting life-threatening reactions, and even death.
Is trihalomethane a carcinogen?
Trihalomethanes are suspect carcinogenic disinfection by-products associated with chlorination of naturally occurring organics in the raw water. Chlorine dioxide is also superior to chlorine when operating above pH 7, in the presence of ammonia and amines and for the control of biofilms in water distribution systems.
Is chlorine dioxide a concentrated gas?
The decomposition can be initiated by light, hot spots, chemical reaction, or pressure shock. Thus, chlorine dioxide gas is never handled in concentrated form, but is almost always handled as a dissolved gas in water in a concentration range of 0.5 to 10 grams per liter.
Is chlorine dioxide a paramagnetic radical?
Chlorine dioxide does not hydrolyze when it enters water; it remains a dissolved gas in solution. Chlorine dioxide is approximately 10 times more soluble in water than chlorine. The molecule ClO 2 has an odd number of valence electrons, and therefore, it is a paramagnetic radical.
What is chlorine dioxide?
Chlorine dioxide is an unstable gas that dissociates into chlorine gas (Cl2), oxygengas (O2) and heat. When chlorine dioxide is photo-oxidized by sunlight, it falls apart. The end-products of chlorine dioxide reactions are chloride (Cl-), chlorite (ClO-) and chlorate (ClO3-).
What is the name of the solution that produces chlorine dioxide?
It is produced in acidic solutions of sodium chlorite (NaClO2), or sodium chlorate (NaClO3). For large installations sodium chlorite, chlorine gas (Cl2), sodium hydrogen chlorite (NaHClO2) and sulphuric or hydrogen acid are used for the production of chlorine dioxide on site.
What is the main application of chlorine dioxide?
Drinking water treatment is the main application of disinfection by chlorine dioxide. Thanks to its adequate biocidal abilities, chlorine dioxide is also used in other branches of industry today. Example are sewage water disinfection, industrial process water treatment, cooling tower water disinfection, industrial air treatment, mussel control, foodstuffs production and treatment, industrial waste oxidation and gas sterilization of medical equipment.
How long does chlorine dioxide stay in water?
In water chlorine dioxide is active as a biocide for at least 48 hours, its activity probaly outranges that of chlorine. Chlorine dioxide prevents the growth of bacteria in the drinking water distribution network. It is also active against the formation of bio film in the distribution network.
How many electrons does chlorine dioxide have?
The chlorine atom in chlorine dioxide has an oxidation number of +4. For this reason chlorine dioxide accepts 5 electrons when it is reduced to chloride. When we look at the molecular weight, chlorine dioxide contains 263 % 'available chlorine'; this is more than 2,5 times the oxidation capacity of chlorine.
How is chlorine dioxide produced?
Chlorine dioxide can also be produced by the reaction of sodium hypochlorite with hydrochloric acid:
Why is chlorine dioxide not stored for long?
At this state it is fairly stable. Chlorine dioxide cannot be stored for too long, because it slowly dissociates into chlorineand oxygen. It is rarely stored as a gas, because it is explosive under pressure. When concentrations are higher than 10% chlorine dioxide in air, there is an explosion hazard.
What compounds does ClO2 react with?
Typically, ClO 2 will react with compounds that have activated carbon bonds such as phenols, or with other active compounds like sulfides, cyanides, and reduced iron and manganese compounds. Because chlorine is a more powerful oxidizer that ClO2, it will react with a wider variety of chemicals, including ammonia.
How does ClO2 destroy microbes?
As a general matter, however, it is known that ClO2 destroys microbes by attacking their cell walls (or viral envelopes) and interfering with essential protein formation.
How many steps does the reaction of ClO2 take?
The reaction of ClO2 with microorganisms or other oxidizable substances takes place in two steps. In the first stage of the reaction, the ClO2 molecule accepts an electron and chlorite ion is formed (ClO2-). In the second stage, ClO2 accepts 4 electrons and chloride ion (Cl-) is formed.
What is high purity clo 2?
High purity ClO 2 has a number of physical and chemical properties that make it the ideal product for addressing liquid, surface and/or airborne microbial contamination in a safe and effective manner.
Is ClO2 a disinfectant?
The propensity of ClO 2 to react by oxidation rather than substitution makes it a useful alternative to chlorine in drinking water disinfection applications where the formation of potentially carcinogenic halogenated disinfection byproducts, such as triholomethanes and halogenated acidic acids, is of concern. Additionally, ClO2 does not produce significant amounts of aldehydes, ketons, keton acids, or other disinfection byproducts that originate from ozonation of water containing organic substances.
Does chlorine dissociate when placed in water?
By way of contrast, chlorine dissociates when placed in water to form hypochlorous and hydrochloric acids. Hypochlorous acid is the primary biocide in solution, which dissociates to form hypochlorite ion with increasing pH. Hypochlorite ion is only from 1/20 to 1/300 as effective in controlling microbes as hypochlorous acid.
Does chlorine penetrate water?
Chlorine has difficulty penetrating this barrier because of its ionic nature in water. ClO 2 readily penetrates through this layer to kill underlying organisms. This quality makes ClO 2 highly effective in controlling cooling tower biofilms.
What is the name of the radical that oxidizes spin traps?
Oxidation of spin-traps by chlorine dioxide (ClO2) radical in aqueous solutions: first ESR evidence of formation of new nitroxide radicals
Is chlorine dioxide a free radical?
The reactivities of the chlorine dioxide (ClO2), which is a stable free radical towards some water-soluble spin-traps were investigated in aqueous solutions by an electron spin resonance (ESR) spectroscopy. The ClO2 radical was generated from the redox reaction of Ti3+ with potassium chlorate (KClO3 …
What is the mechanism of oxidation of chlorine dioxide?
Like ozone, the predominant oxidation reaction mechanism for chlorine dioxide proceeds through a process known as free radical electrophilic (i.e. electron-attracting) abstraction rather than by oxidative substitution or addition (as in chlorinating agents such as chlorine or hypochlorite).
How many electrons does chlorine dioxide absorb?
However, chlorine has the capacity to take in two electrons, whereas chlorine dioxide can absorb five . This means that, mole for mole, ClO 2 is 2.6 times more effective than chlorine. If equal, if not greater importance is the fact that chlorine dioxide will not react with many organic compounds, and as a result ClO 2 does not produce ...
Is chlorine dioxide a chemical?
While chlorine dioxide has “ chlorine” in its name, its chemistry is radically different from that of chlorine. As we all learned in high school chemistry, we can mix two compounds and create a third that bears little resemblance to its parents. For instance, by mixing two parts of hydrogen gas with one of oxygen - liquid water is the formed.
Is chlorine dioxide more effective than chlorine?
However, chlorine has the capacity to take in two electrons, whereas chlorine dioxide can absorb five. This means that, mole for mole, ClO 2 is 2.6 times more effective than chlorine.
What are free radicals?
free radicals are atoms or molecules which contain unpaired electrons. Since electrons have a very strong tendency to exist in a paired rather than an unpaired state, free radicals indiscriminately pick up electrons from other atoms, which in turn converts those other atoms into secondary free radicals, thus setting up a chain reaction which can cause substantial biological damage.
Who discovered the free radical?
The first time I saw the word "free radical" I didn't have a clue as to what it meant. Within a few more days I had read a great deal about it. Dr. Denham Harmon became very famous for having "discovered" free radicals or, more accurately, for developing the "free radical concept of aging."
How do free radicals affect the body?
Free radicals occur naturally as products of oxidation and are formed in the body during respiration and other chemical processes. Exposure to pollution, cigarette smoke, and strong sunlight can increase the formation of free radicals. Once in the body, free radicals can damage tissues and delicate cell membranes. They can also damage DNA, disrupting our store of inherited information; this may lead to the initiation of certain cancers. Medical scientists believe that free radicals also contribute to at least fifty other major diseases including atherosclerosis, heart disease, rheumatoid arthritis, and lung disease. They may even accelerate the ageing process. Fortunately, our bodies have a good defence system to deal with free radicals. The system is based on chemicals, such as the enzyme sodium dismutase, which can donate electrons to the free radicals, quelling their hyper-reactivity. Chemicals in food, called antioxidants, also disarm free radicals. These antioxidants include beta-carotene, and vitamins A, C, and E.
What does it mean when a radical is unpaired?
The more complete answer is that a "free radical" is any atom or molecule which has an "unpaired electron" in the outer ring. An "unpaired electron" will also always mean that there is an odd number since "pairing" of electrons goes by 2s.
Why is free radical damage considered a basic mechanism of tissue injury?
Hence, this free radical generation process can disrupt all levels of cell function. This is why free radical damage is thought to be such a basic mechanism of tissue injury. It damages us at the cellular level.
How do free radicals increase?
Free radicals are increased in activity and quantity by bumping into toxic metals in the body. Thus, toxic metals are a cause of free radicals. Several hundred years ago we did NOT have the burden of toxic metals in our bodies that we now do, and we also did not have such an exposure to free radicals. If you remove the toxic metals from the body, you then greatly reduce the activity and the number of free radicals.
What are the lipids in the cell membrane?
Cell membranes are made of unsaturated lipids. The unsaturated lipid molecules of cell membranes are particularly susceptible to this damaging free radicals process and readily contribute to the uncontrolled chain reaction. Oxidative damage, another name for the chemical reaction that free radicals cause, can lead to a breakdown or even hardening of lipids, which makeup all cell walls. If the cell wall is hardened (lipid peroxidation) then it becomes impossible for the cell to properly get its nutrients, get signals from other cells to perform an action (such as firing of a neuron) and many other cellular activities can be affected. In addition to the cell walls, other biological molecules are also susceptible to damage, including RNA, DNA and protein enzymes.
How to avoid free radicals?
Avoid high glycemic foods, or foods that are rich in refined carbohydrates and sugars. They are more likely to generate free radicals. Limit processed meats such as sausages, bacon and salami. They contain preservatives, which leads to the production of free radicals.
What are some examples of free radicals?
Beside above, what are examples of free radicals? A notable example of a free radical is the hydroxyl radical (HO•), a molecule that is one hydrogen atom short of a water molecule and thus has one bond "dangling" from the oxygen.
What is a molecule with one or more unpaired electrons called?
A molecule with one or more unpaired electron in its outer shell is called a free radical (1-5) . Free radicals are formed from molecules via the breakage of a chemical bond such that each fragment keeps one electron, by cleavage of a radical to give another radical and, also via redox reactions (1, 2).
What are radicals in biology?
Radicals (often referred to as free radicals) are atoms, molecules, or ions with unpaired electrons on an open shell configuration. Free radicals may have positive, negative, or zero charge. With some exceptions, the unpaired electrons cause radicals to be highly chemically reactive.
What is the difference between a neutral radical and an anion?
The main difference is that a neutral radical has no charge imbalance between the protons and electrons, but the cation or anion does. Ions are written with an explicit charge because of that charge imbalance, but radicals may or may not have an imbalance of charge.
Is chlorine dioxide a free radical?
The reactivities of the chlorine dioxide (ClO2), which is a stable free radical towards some water-soluble spin-traps were investigated in aqueous solutions by an electron spin resonance (ESR) spectroscopy.
Is a basic radical an ion?
Basic radical is an ion coming from a base. It is a positively charged chemical species; thus we name it as the cation. Moreover, it is a portion of an inorganic salt. This ion forms as a result of the removal of a hydroxide ion from a base.
Overview
Chlorine dioxide is a chemical compound with the formula ClO2 that exists as yellowish-green gas above 11 °C, a reddish-brown liquid between 11 °C and −59 °C, and as bright orange crystals below −59 °C. It does not hydrolyze when it enters water, and is usually handled as an aqueous solution. Potential hazards with chlorine dioxide include poisoning and the risk of spontaneous ignition or explosion on contact with flammable materials. It is also commonly used as a bleach.
Structure and bonding
Chlorine dioxide is a neutral chlorine compound. It is very different from elemental chlorine, both in its chemical structure and in its behavior. One of the most important qualities of chlorine dioxide is its high water solubility, especially in cold water. Chlorine dioxide does not react with water; it remains a dissolved gas in solution. Chlorine dioxide is approximately 10 times more sol…
Properties
Chlorine dioxide is a reddish-yellow gas at standard temperature and pressure. It is somewhat unstable, and strong acids can decompose it into chlorine and oxygen. For this reason, it is dangerous to add sulfuric acid or any strong acid to a solid chlorate because of the production of chlorine dioxide.
A solution of chlorine dioxide in water is yellow to yellowish-brown.
Preparation
Chlorine dioxide is a compound that can decompose extremely violently when separated from diluting substances. As a result, preparation methods that involve producing solutions of it without going through a gas-phase stage are often preferred. Arranging handling in a safe manner is essential.
In the laboratory, ClO2 can be prepared by oxidation of sodium chlorite with chlorine:
Handling properties
At partial pressures above 10 kPa (1.5 psi) (or gas-phase concentrations greater than 10% volume in air at STP) of ClO2 may explosively decompose into chlorine and oxygen. The decomposition can be initiated by light, hot spots, chemical reaction, or pressure shock. Thus, chlorine dioxide gas is never handled in concentrated form, but is almost always handled as a dissolved gas in water in a concentration range of 0.5 to 10 grams per liter. Its solubility increases at lower temperatures, th…
Uses
Chlorine dioxide is used for bleaching of wood pulp and for the disinfection (called chlorination) of municipal drinking water, treatment of water in oil and gas applications, disinfection in the food industry, microbiological control in cooling towers, and textile bleaching. As a disinfectant, it is effective even at low concentrations because of its unique qualities.
Chlorine dioxide is sometimes used for bleaching of wood pulp in combination with chlorine, bu…
Safety issues in water and supplements
Chlorine dioxide is toxic, hence limits on exposure to it are needed to ensure its safe use. The United States Environmental Protection Agency has set a maximum level of 0.8 mg/L for chlorine dioxide in drinking water. The Occupational Safety and Health Administration (OSHA), an agency of the United States Department of Labor, has set an 8-hour permissible exposure limit of 0.1 ppm in air (0.3 mg/m ) for people working with chlorine dioxide.
External links
• Media related to chlorine dioxide at Wikimedia Commons