Potassium chlorate is a compound containing potassium and oxygen, with the molecular formula KClO3. In its pure form, it is a white crystalline substance, it is the most common chlorate in industrial use. It is used as an oxidizing agent, to prepare oxygen, as a disinfectant, in safety matches, in explosives and fireworks, in cultivation, forcing the blossoming stage of the longan tree, causing it to produce fruit in warmer climates. On the industrial scale, potassium chlorate is produced by the Liebig process: passing chlorine into hot calcium hydroxide, subsequently adding potassium chloride: 6 Ca2 + 6 Cl2 → Ca2 + 5 CaCl2 + 6 H2O Ca2 + 2 KCl → 2 KClO3 + CaCl2The electrolysis of KCl in aqueous solution is used sometimes, in which elemental chlorine formed at the anode react with KOH in situ; the low solubility of KClO3 in water causes the salt to conveniently isolate itself from the reaction mixture by precipitating out of solution. Potassium chlorate can be produced in small amounts by disproportionation in a sodium hypochlorite solution followed by metathesis reaction with potassium chloride: 3 NaOCl → 2 NaCl + NaClO3 KCl + NaClO3 → NaCl + KClO3It can be produced by passing chlorine gas into a hot solution of caustic potash: 3 Cl2 + 6 KOH → KClO3 + 5 KCl + 3 H2O Potassium chlorate was one key ingredient in early firearms percussion caps.
It continues in that application. Chlorate-based propellants are more efficient than traditional gunpowder and are less susceptible to damage by water. However, they can be unstable in the presence of sulfur or phosphorus and are much more expensive. Chlorate propellants must be used only in equipment designed for them. Potassium chlorate in combination with silver fulminate, is used in trick noise-makers known as "crackers", "snappers", "pop-its", or "bang-snaps", a popular type of novelty firework. Another application of potassium chlorate is as the oxidizer in a smoke composition such as that used in smoke grenades. Since 2005, a cartridge with potassium chlorate mixed with lactose and rosin is used for generating the white smoke signalling the election of new pope by a papal conclave. Potassium chlorate is used in high school and college laboratories to generate oxygen gas, it is a far cheaper source than a cryogenic oxygen tank. Potassium chlorate decomposes if heated while in contact with a catalyst manganese dioxide.
Thus, it may be placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off; the reaction is as follows: 2 KClO3 → 3 O2 + 2 KClHeating it in the absence of a catalyst converts it into potassium perchlorate: 4 KClO3 → 3 KClO4 + KClWith further heating, potassium perchlorate decomposes to potassium chloride and oxygen: KClO4 → KCl + 2 O2The safe performance of this reaction requires pure reagents and careful temperature control. Molten potassium chlorate is an powerful oxidizer and spontaneously reacts with many common materials such as sugar. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators, as well as from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can cause problems; when working with a new batch of potassium chlorate, it is advisable to take a small sample and heat it on an open glass plate. Contamination may cause this small quantity to explode, indicating that the chlorate should be discarded.
Potassium chlorate is used in chemical oxygen generators, employed as oxygen-supply systems of e.g. aircraft, space stations, submarines, has been responsible for at least one plane crash. A fire on the space station Mir was traced to this substance; the decomposition of potassium chlorate was used to provide the oxygen supply for limelights. Potassium chlorate is used as a pesticide. In Finland it was sold under trade name Fegabit. Potassium chlorate can react with sulfuric acid to form a reactive solution of chloric acid and potassium sulfate: 2 KClO3 + H2SO4 → 2 HClO3 + K2SO4The solution so produced is sufficiently reactive that it spontaneously ignites if combustible material is present. In schools, molten potassium chlorate is used in the dramatic screaming jelly babies demonstration. In chemical labs it is used to release small amounts of gaseous chlorine. Insurgents in Afghanistan use potassium chlorate extensively as a key component in the production of improvised explosive devices; when significant effort was made to reduce the availability of ammonium nitrate fertilizer in Afghanistan, IED makers started using potassium chlorate as a cheap and effective alternative.
In 2013, 60% of IEDs in Afghanistan used potassium chlorate, making it the most common ingredient used in IEDs. Potassium Chlorate was the main ingredient in the car bomb used in 2002 Bali bombings that killed 202 people. Potassium chlorate should be handled with care, it reacts vigorously, in some cases spontaneously ignites or explodes, when mixed with many combustible materials. It burns vigorously in combination with any combustible material those only flammable. Mixtures of potassium chlorate and a fuel can ignite by contact with sulfuric acid, so it should be kept away from this reagent. Sulfur should be avoided in pyrotechnic compositions containing potassium chlorate, as these mixtures are prone to spontaneous deflagration. Most sulfur contains
Jonathan David Sarfati is a young Earth creationist who writes articles for Creation Ministries International, a non-profit Christian Apologetics ministry. Sarfati has a PhD in chemistry, was New Zealand national chess champion in 1987 and 1988. Born in Ararat, Sarfati moved with his family to New Zealand as a child, where he became a dual Australian and New Zealand citizen, he attended Wellington College in New Zealand graduating from Victoria University of Wellington with a B. Sc. in chemistry, a Ph. D. in the same subject for a thesis entitled "A Spectroscopic Study of some Chalcogenide Ring and Cage Molecules". He co-authored a paper on high-temperature superconductors, published in Nature in 1987, from 1988 to 1995, had several papers on spectroscopy of condensed matter samples published in other peer-reviewed scientific journals. In 1996, he returned to Brisbane, Australia to work for the Creation Science Foundation Answers in Genesis its current name Creation Ministries International. In 2010, he moved to the American office of that ministry.
Sarfati was a founder of the Wellington Christian Apologetics Society in New Zealand, has long retained an interest in Christian apologetics and the creation-evolution controversy. His first two books, Refuting Evolution in 1999, Refuting Evolution 2 in 2002, are intended as rebuttals to the National Academy of Sciences' publication Teaching about Evolution and the Nature of Science and the PBS/Nova series Evolution, respectively. Refuting Compromise, published in 2004, is Sarfati's rebuttal of the day-age creationist teachings of Dr. Hugh Ross, who attempts to harmonise the Genesis account of creation with mainstream science regarding the age of the earth and the possible size of the Biblical Flood, against which Sarfati defends a literal biblical timeline and a global flood. Eugenie Scott and Glenn Branch of the National Center for Science Education called Sarfati's Refuting Evolution 2 a "crude piece of propaganda". Sarfati is a critic of geocentrism, the Myth of the flat Earth and flat earth teaching, homosexual behaviour, abortion except to save the life of the mother.
While opposing embryonic stem cell research, he supports adult stem cell research. Sarfati supports vaccination and rebuts anti-vaccination arguments. Sarfati is a FIDE Master in chess, achieved a draw against former world champion Boris Spassky during a tournament in Wellington in 1988, was New Zealand's national chess champion in 1987–88. Although tied with Rey Casse for first place in the Australian Junior Championship of 1981, he was not eligible to share the title as he was a resident of New Zealand at the time, he represented New Zealand in three Chess Olympiads: the 27th in Dubai in 1986, the 28th in Thessaloniki in 1988, the 30th in Manila in 1992. He represented New Zealand on top board at the 5th Asian Teams in New Delhi, he has given blindfold chess exhibitions at chess clubs and other events, has played twelve such games simultaneously. His previous best was winning 11/11 at the Kapiti Chess Club in New Zealand; the Genesis Account: A theological and scientific commentary on Genesis 1-11, 2015, Creation Book Publishers ISBN 978-1921643910 Christianity for Skeptics, 2012, with Steve Kumar, Creation Book Publishers ISBN 978-1921643491 The Greatest Hoax on Earth?
Refuting Dawkins on Evolution, 2010, Creation Book Publishers ISBN 1-921643-06-4 By Design: Evidence for nature's Intelligent Designer—the God of the Bible, 2008, Creation Book Publishers ABN: 978-0-949906-72-4 Refuting Compromise: A Biblical and Scientific Refutation of Progressive Creationism, 2004, Creation Book Publishers ISBN 0-89051-411-9 The Revised & Expanded Answers Book, 2003, with Carl Wieland and David Catchpoole, edited by Don Batten, ISBN 0-89051-395-3 Refuting Evolution 2, 2002/2011, Creation Book Publishers ISBN 0-89051-387-2 Refuting Evolution, 1999-2010, Creation Book Publishers ISBN 0-89051-258-2
A match is a tool for starting a fire. Modern matches are made of small wooden sticks or stiff paper. One end is coated with a material that can be ignited by frictional heat generated by striking the match against a suitable surface. Wooden matches are packaged in matchboxes, paper matches are cut into rows and stapled into matchbooks; the coated end of a match, known as the match "head", consists of a bead of active ingredients and binder. There are two main types of matches: safety matches, which can be struck only against a specially prepared surface, strike-anywhere matches, for which any suitably frictional surface can be used; the term match referred to lengths of cord impregnated with chemicals, allowed to burn continuously. These were used to fire guns and cannons; such matches were characterised by their burning speed i.e. slow match. Depending on its formulation, a slow match burns at a rate of around 30 cm per hour and a quick match at 4 to 60 centimetres per minute; the modern equivalent of this sort of match is the simple fuse, still used in pyrotechnics to obtain a controlled time delay before ignition.
The original meaning of the word still persists in some pyrotechnics terms, such as black match and Bengal match. But, when friction matches became commonplace, they became the main object meant by the term; the word "match" derives from Old French "mèche" referring to the wick of a candle. A note in the text Cho Keng Lu, written in 1366, describes a sulfur match, small sticks of pinewood impregnated with sulfur, used in China by "impoverished court ladies" in AD 577 during the conquest of Northern Qi. During the Five Dynasties and Ten Kingdoms, a book called the Records of the Unworldly and the Strange written by Chinese author Tao Gu in about 950 stated: If there occurs an emergency at night it may take some time to make a light to light a lamp, but an ingenious man devised the system of impregnating little sticks of pinewood with sulfur and storing them ready for use. At the slightest touch of fire, they burst into flame. One gets a little flame like an ear of corn; this marvelous thing was called a "light-bringing slave", but afterward when it became an article of commerce its name was changed to'fire inch-stick'.
Another text, Wu Lin Chiu Shih, dated from 1270 AD, lists sulfur matches as something, sold in the markets of Hangzhou, around the time of Marco Polo's visit. The matches were known as fa tshui erh. Prior to the use of matches, fires were sometimes lit using a burning glass to focus the sun on tinder, a method that could only work on sunny days. Another more common method was igniting tinder with sparks produced by striking flint and steel, or by increasing air pressure in a fire piston. Early work had been done by alchemist Hennig Brand, who discovered the flammable nature of phosphorus in 1669. Others, including Robert Boyle and his assistant, Ambrose Godfrey, continued these experiments in the 1680s with phosphorus and sulfur, but their efforts did not produce practical and inexpensive methods for generating fires. A number of different ways were employed in order to light smoking tobacco: One was the use of a spill — a thin object something like a straw, rolled paper, or a thin candle, which would be lit from a nearby existing flame and used to light the pipe or cigar — most kept near the fireplace in a spill vase.
Another method saw the use of a striker, a tool that looked like scissors, but with flint on one "blade" and steel on the other. These would be rubbed together producing sparks. If neither of these two was available, one could use ember tongs to pick up a coal from a fire and light the tobacco directly; the first modern, self-igniting match was invented in 1805 by Jean Chancel, assistant to Professor Louis Jacques Thénard of Paris. The head of the match consisted of a mixture of potassium chlorate, sulfur and rubber; the match was ignited by dipping its tip in a small asbestos bottle filled with sulfuric acid. This kind of match was quite expensive and its use was relatively dangerous, so Chancel's matches never became adopted or in commonplace use; this approach to match making was further refined in the proceeding decades, culminating with the'Promethean Match', patented by Samuel Jones of London in 1828. His match consisted of a small glass capsule containing a chemical composition of sulfuric acid colored with indigo and coated on the exterior with potassium chlorate, all of, wrapped up in rolls of paper.
The immediate ignition of this particular form of a match was achieved by crushing the capsule with a pair of pliers and releasing the ingredients in order for it to become alight. In London, similar matches meant for lighting cigars were introduced in 1849 by Heurtner who had a shop called the Lighthouse in the Strand. One version that he sold was called "Euperion", popular for kitchen use and nicknamed as "Hugh Perry", while another meant for outdoor use was called a "Vesuvian" or "flamer"; the head was large and contained niter and wood dust, had a phosphorus tip. The handle was large and made of hardwood so as to burn last for a while; some had glass stems. Both Vesuvians and Prometheans had a bulb of sulfuric acid at the tip which had to be broken to start the reaction. Samuel Jones introduced fuzees for lighting cigars and pipes in 1832. A similar invention was patented in 1839 by John Hucks Stevens in America. In 1832
Occupational safety and health
Occupational safety and health commonly referred to as occupational health and safety, occupational health, or workplace health and safety, is a multidisciplinary field concerned with the safety and welfare of people at work. These terms refer to the goals of this field, so their use in the sense of this article was an abbreviation of occupational safety and health program/department etc; the goals of occupational safety and health programs include to foster a safe and healthy work environment. OSH may protect co-workers, family members, employers and many others who might be affected by the workplace environment. In the United States, the term occupational health and safety is referred to as occupational health and occupational and non-occupational safety and includes safety for activities outside of work. In common-law jurisdictions, employers have a common law duty to take reasonable care of the safety of their employees. Statute law may in addition impose other general duties, introduce specific duties, create government bodies with powers to regulate workplace safety issues: details of this vary from jurisdiction to jurisdiction.
As defined by the World Health Organization "occupational health deals with all aspects of health and safety in the workplace and has a strong focus on primary prevention of hazards." Health has been defined as "a state of complete physical and social well-being and not the absence of disease or infirmity." Occupational health is a multidisciplinary field of healthcare concerned with enabling an individual to undertake their occupation, in the way that causes least harm to their health. Health has been defined as It contrasts, for example, with the promotion of health and safety at work, concerned with preventing harm from any incidental hazards, arising in the workplace. Since 1950, the International Labour Organization and the World Health Organization have shared a common definition of occupational health, it was adopted by the Joint ILO/WHO Committee on Occupational Health at its first session in 1950 and revised at its twelfth session in 1995. The definition reads: "The main focus in occupational health is on three different objectives: the maintenance and promotion of workers’ health and working capacity.
The concept of working culture is intended in this context to mean a reflection of the essential value systems adopted by the undertaking concerned. Such a culture is reflected in practice in the managerial systems, personnel policy, principles for participation, training policies and quality management of the undertaking." Those in the field of occupational health come from a wide range of disciplines and professions including medicine, epidemiology and rehabilitation, occupational therapy, occupational medicine, human factors and ergonomics, many others. Professionals advise on a broad range of occupational health matters; these include how to avoid particular pre-existing conditions causing a problem in the occupation, correct posture for the work, frequency of rest breaks, preventative action that can be undertaken, so forth. "Occupational health should aim at: the promotion and maintenance of the highest degree of physical and social well-being of workers in all occupations. The research and regulation of occupational safety and health are a recent phenomenon.
As labor movements arose in response to worker concerns in the wake of the industrial revolution, worker's health entered consideration as a labor-related issue. In the United Kingdom, the Factory Acts of the early nineteenth century arose out of concerns about the poor health of children working in cotton mills: the Act of 1833 created a dedicated professional Factory Inspectorate; the initial remit of the Inspectorate was to police restrictions on the working hours in the textile industry of children and young persons. However, on the urging of the Factory Inspectorate, a further Act in 1844 giving similar restrictions on working hours for women in the textile industry introduced a requirement for machinery guarding. In 1840 a Royal Commission published its findings on the state of conditions for the workers of the mining industry that documented the appallingly dangerous environment that they had to work in and the high frequency of accidents; the commission sparked public outrage which resulted in the Mines Act of 1842.
The act set up an inspectorate for mines and collieries which resulted in many prosecutions and safety improvements, by 1850, inspectors were able to enter and inspect premises at their discretion. Otto von Bismarck inaugurated the first social insurance legislation in 1883 and the first worker's compensation law in 1884 – the first of their kind in the Western world. Similar acts followed in other countries
Phosphorus sulfides comprise a family of inorganic compounds containing only phosphorus and sulfur. These compounds have the formula P4Sx with x ≤ 10. Two are of commercial significance, phosphorus pentasulfide, made on a kiloton scale for the production of other organosulfur compounds, phosphorus sesquisulfide, used in the production of "strike anywhere matches". There are several other phosphorus sulfides in addition to P4S3 and P4S10. Six of these phosphorus sulfides exist as isomers: P4S4, P4S5, P4S6, P4S7, P4S8, P4S9; these isomers are distinguished by Greek letter prefixes. The prefix is based on the order of the discovery of the isomers, not their structure. All known molecular phosphorus sulfides contain a tetrahedral array of four phosphorus atoms. P4S2 is known but is unstable above −30 °C; the main method for preparing these compounds is thermolysis of mixtures of sulfur. The product distributions can be analyzed by 31P NMR spectroscopy. More selective syntheses entail desulfurization, e.g. using triphenylphosphine and, sulfidation using triphenylarsine sulfide.
Phosphorus sesquisulfide is prepared by treating red phosphorus with sulfur above 450 K, followed by careful recrystallization with carbon disulfide and benzene. An alternative method involves the controlled fusion of white phosphorus with sulfur in an inert, non-flammable solvent; the α- and β- forms of P4S4 can be prepared by treating the corresponding isomers of P4S3I2 with 2S: P4S3I2 can be synthesized by the reaction of stoichiometric amounts of phosphorus and iodine. P4S5 can be prepared by treating stoichiometric amounts of P4S3 with sulfur in carbon disulfide solution, in the presence of light and a catalytic amount of iodine; the respective product distribution is analyzed by using 31P NMR spectroscopy. In particular, α-P4S5 can be made by the photochemical reaction of P4S10 with red phosphorus. Note that P4S5 is unstable when heated, tending to disproportionate to P4S3 and P4S7 before reaching its melting point. P4S6 can be made by abstracting a sulfur atom from P4S7 using triphenylphosphine: P4S7 + Ph3P → P4S6 + Ph3PSThe two new polymorphs δ-P4S6 and ε-P4S6 can be made by treating α-P4S4 with Ph3SbS in CS2.
P4S7 is most conveniently made by direct union of the corresponding elements, is one of the most purified binary phosphorus sulfides. 4 P + 7 S → P4S7 P4S9 can be made by two methods. One method involves the heating of P4S3 in excess sulfur. Another method involves the heating of P4S7 and P4S10 in 1:2 mole ratio, where P4S9 is reversibly formed: P4S7 + 2 P4S10 ⇌ 3 P4S9 P4S10 is one of the most stable phosphorus sulfides, it is most made by heating white phosphorus with sulfur above 570 K in an evacuated tube. P4 + 10 S → P4S10
Phosphorus pentabromide is a reactive, yellow solid of formula PBr5, which has the structure PBr4+ Br− in the solid state but in the vapor phase is dissociated to PBr3 and Br2. Rapid cooling of this phase to 15 K leads to formation of the ionic species phosphorus heptabromide, it can be used in organic chemistry to convert carboxylic acids to acyl bromides. It is corrosive, it decomposes above 100 °C to give phosphorus tribromide and bromine: PBr5 → PBr3 + Br2Reversing this equilibrium to generate PBr5 by addition of Br2 to PBr3 is difficult in practice because the product is susceptible to further addition to yield phosphorus heptabromide
Allotropes of phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are known. Gaseous phosphorus exists as atomic phosphorus. White phosphorus, yellow phosphorus or tetraphosphorus exists as molecules made up of four atoms in a tetrahedral structure; the tetrahedral arrangement results in ring instability. The molecule is described as consisting of six single P–P bonds. Two different crystalline forms are known; the α form is defined as the standard state of the element, but is metastable under standard conditions. It has a body-centered cubic crystal structure, transforms reversibly into the β form at 195.2 K. The β form is believed to have a hexagonal crystal structure. White phosphorus is a translucent waxy solid that becomes yellow when exposed to light. For this reason it is called yellow phosphorus, it glows greenish in the dark and is flammable and pyrophoric upon contact with air. It is toxic, causing severe liver damage on ingestion and phossy jaw from chronic ingestion or inhalation.
The odour of combustion of this form has a characteristic garlic smell, samples are coated with white "diphosphorus pentoxide", which consists of P4O10 tetrahedral with oxygen inserted between the phosphorus atoms and at their vertices. White phosphorus is only soluble in water and can be stored under water. Indeed, white phosphorus is safe from self-igniting only, it is soluble in benzene, carbon disulfide, disulfur dichloride. The white allotrope can be produced using several different methods. In the industrial process, phosphate rock is heated in an electric or fuel-fired furnace in the presence of carbon and silica. Elemental phosphorus is liberated as a vapour and can be collected under phosphoric acid. An idealized equation for this carbothermal reaction is shown for calcium phosphate: 2 Ca32 + 6 SiO2 + 10 C → 6 CaSiO3 + 10 CO + P4 White phosphorus has an appreciable vapour pressure at ordinary temperatures; the vapour density indicates that the vapour is composed of P4 molecules up to about 800 °C.
Above that temperature, dissociation into P2 molecules occurs. It ignites spontaneously in air at about 50 °C, at much lower temperatures if finely divided; this combustion gives phosphorus oxide: P4 + 5 O2 → P4O10Because of this property, white phosphorus is used as a weapon. Although white phosphorus converts to the thermodynamically more stable red allotrope, the formation of the cubic P8 molecule is not observed in the condensed phase. Analogs of this hypothetical molecule have been prepared from phosphaalkynes. Red phosphorus may be formed by heating white phosphorus to 300 °C in the absence of air or by exposing white phosphorus to sunlight. Red phosphorus exists as an amorphous network. Upon further heating, the amorphous red phosphorus crystallizes. Red phosphorus does not ignite in air at temperatures below 240 °C, whereas pieces of white phosphorus ignite at about 30 °C. Ignition is spontaneous at room temperature with finely divided material. Under standard conditions it is more stable than white phosphorus, but less stable than the thermodynamically stable black phosphorus.
The standard enthalpy of formation of red phosphorus is -17.6 kJ/mol. Red phosphorus can be used as a effective flame retardant in thermoplastics and thermosets; the flame retarding effect is based on the formation of polyphosphoric acid. Together with the organic polymer material, this acid creates a char which prevents the propagation of the flames; the safety risks associated with phosphine generation and friction sensitivity of red phosphorus can be reduced by stabilization and micro-encapsulation. For easier handling, red phosphorus is used in form of dispersions or masterbatches in various carrier systems. However, for electronic/electrical systems, red phosphorus flame retardant has been banned by major OEMs due to its tendency to induce premature failures. There have been two issues over the years: the first was red phosphorus in epoxy molding compounds inducing elevated leakage current in semiconductor devices and the second was acceleration of hydrolysis reactions in PBT insulating material.
Red phosphorus can be used in the illicit production of narcotics, including some recipes for methamphetamine. Red phosphorus can be used as an elemental photocatalyst for hydrogen formation from the water, they display a steady hydrogen evolution rates of 633ℳmol/ by the formation of small-sized fibrous phosphorus. Monoclinic phosphorus, or violet phosphorus, is known as Hittorf's metallic phosphorus. In 1865, Johann Wilhelm Hittorf heated red phosphorus in a sealed tube at 530 °C; the upper part of the tube was kept at 444 °C. Brilliant opaque monoclinic, or rhombohedral, crystals sublimed as a result. Violet phosphorus can be prepared by dissolving white phosphorus in molten lead in a sealed tube at 500 °C for 18 hours. Upon slow cooling, Hittorf's allotrope crystallises out; the crystals can be revealed by dissolving the lead in dilute nitric acid followed by boiling in concentrated hydrochloric acid. In addition, a fibrous form exists with similar phosphorus cages, it is insoluble in all solvents.
It is not attacked by alkali and only reacts with halogens. It can be oxidised by nitric acid to phosphoric acid. If it is heated in an atmosphere of inert gas, for example nitrogen or carbon dioxide, it sublimes and the vapour condenses as white phosphorus. If it is