Potassium chlorate decomposition

Unexpectedly we find that the bromate(V) ion in acid solution (i.e. effectively bromic(V) acid) is a more powerful oxidising agent than the chlorate(V) ion, CIO3. The halates(V) are thermally unstable and can evolve oxygen as one of the decomposition products. Potassium chlorate(V), when heated, first melts, then resolidifies due to the formation of potassium chlorate(VII) (perchlorate) ... 

The decomposition of potassium chlorate(V) is catalysed by manganese(IV) oxide, Mn02, and oxygen is evolved on heating the mixture below the melting point of the chlorate(V). 

It catalyses the decomposition of potassium chlorate(V). Mixed with zinc oxide, it is used as a catalyst in the manufacture of methanol. It is used as a pigment, being very resistant to weathering. 

Potassium iodate [7758-05-6] KIO, mol wt 214.02, 59.30% I, forms white, odorless crystals or a crystalline powder. It has a density 3.98 g/mL and mp of 560°C with partial decomposition. Potassium iodate is rapidly formed when potassium iodide is fused with potassium chlorate, bromate, or perchlorate. The solubihty in water is 9.16 g/100 g H2O at 25°C and 32.2 g/100 g H2O at 100°C. KIO is extensively used as an oxidizing agent in analytical chemistry and as amaturing agent and dough conditioner (see Bakery processes and leavening agents). 

Pyrotechnic mixtures may also contain additional components that are added to modify the bum rate, enhance the pyrotechnic effect, or serve as a binder to maintain the homogeneity of the blended mixture and provide mechanical strength when the composition is pressed or consoHdated into a tube or other container. These additional components may also function as oxidizers or fuels in the composition, and it can be anticipated that the heat output, bum rate, and ignition sensitivity may all be affected by the addition of another component to a pyrotechnic composition. An example of an additional component is the use of a catalyst, such as iron oxide, to enhance the decomposition rate of ammonium perchlorate. Diatomaceous earth or coarse sawdust may be used to slow up the bum rate of a composition, or magnesium carbonate (an acid neutralizer) may be added to help stabilize mixtures that contain an acid-sensitive component such as potassium chlorate. Binders include such materials as dextrin (partially hydrolyzed starch), various gums, and assorted polymers such as poly(vinyl alcohol), epoxies, and polyesters. Polybutadiene mbber binders are widely used as fuels and binders in the soHd propellant industry. The production of colored flames is enhanced by the presence of chlorine atoms in the pyrotechnic flame, so chlorine donors such as poly(vinyl chloride) or chlorinated mbber are often added to color-producing compositions, where they also serve as fuels. 

Several common acid treatments for sample decomposition include the use of concentrated nitric acid, aqua regia, nitric—sulfuric acids, and nitric perchloric acids. Perchloric acid is an effective oxidant, but its use is ha2ardous and requkes great care. Addition of potassium chlorate with nitric acid also assists in dissolving any carbonaceous matter. 

Chemical Properties. On thermal decomposition, both sodium and potassium chlorate salts produce the corresponding perchlorate, salt, and oxygen (32). Mixtures of potassium chlorate and metal oxide catalysts, especially manganese dioxide [1313-13-9] Mn02, are employed as a laboratory... 

Oxygen occurs free in air in which it forms 21% by volume. It is also found combined with hydrogen in water and constitutes 86% of the oceans, and with other elements such as minerals constituting ca 50% of the earth s crust. In the laboratory it is usually prepared by the thermal decomposition of potassium chlorate in the presence of manganese dioxide catalyst ... 

Write the balanced chemical equation for (a) the thermal decomposition of potassium chlorate without a catalyst (b) the reaction of bromine with water (c) the reaction between sodium chloride and concentrated sulfuric acid, (d) Identify each reaction as a Bronsted acid—base, Lewis acid—base, or redox reaction. 

C04-0012. When heated, potassium chlorate decomposes to potassium chloride and gaseous molecular oxygen 2 KCIO3 2KC1 + 3 O2 What is the theoretical yield of oxygen when 5.00 g of potassium chlorate decomposes Calculate the percent yield if a 5.00-g sample gives 1.84 g O2 on decomposition. Give possible reasons why the actual yield is less than the theoretical yield. 

Sodium chlorate stored in closed containers detonated because of its confinement and the heat given off by a nearby fire. For a reason that was not specified, a stock of 80 tonnes of potassium chlorate detonated. Regarding this accident the authors make the assumption that the decomposition reaction of this compound would be the following ... 

When mixed with potassium chlorate calcium dihydrogenphosphate detonates as violently as with decomposition of nitroglycerine. It is probably the result of the explosive decomposition of chlorine dioxide, which is formed because of the presence of acid radicals in the phosphate. 

Theoretically, all chemical reactions are reversible. There are, however, many reactions in which the extent of the reverse reaction (i.e., combination of the products to produce the reactants) is very small as to be considered negligible. Such reactions which are ordinarily found to proceed to completion in one direction are said to be irreversible reactions. The decomposition of potassium chlorate... 

Action of chlorine trifluoride causes incandescence [1]. Manganese dioxide catalytically decomposes powerful oxidising agents, often violently. Dropped into cone, hydrogen peroxide, the powdered oxide may cause explosion [2], Either the massive or the powdered oxide explosively decomposes 92% peroxomonosulfuric acid [3], and mixtures with chlorates ( oxygen mixture , heated to generate the gas) may react with explosive violence [4], Cuban pyrolusite can be used in place of potassium dichromate to promote thermal decomposition of potassium chlorate in match-head formulations [5],... 

The halic acids may not be industrially important, but their salts certainly are. Sodium chlorate is produced in enormous quantities and used in processes in which its oxidizing strength makes it a versatile bleach. One such use is in making paper, and potassium chlorate is used as the oxidizing agent in matches. The decomposition of potassium chlorate was discussed in Chapter 13 in connection with the laboratory preparation of oxygen. 

Decomposition reactions are reactions in which a compound breaks down into two or more simpler substances. Although not all decomposition reactions are redox reactions, many are. For example, the thermal decomposition reactions, such as the common laboratory experiment of generating oxygen by heating potassium chlorate, are decomposition reactions ... 

What mass of oxygen, O2, can be obtained by the decomposition of 5.0 g of potassium chlorate, KCIO3 The balanced equation is given below. 2KCIO3 2KC1 + 3O2... 

Pyrotechnic mixtures "burn," but it must be remembered that these materials supply their OWTl oj gen for combustion, through the thermal decomposition of an oxygen-rich material such as potassium chlorate... 

Several factors contribute to the instability of potassium chlorate-containing compositions. The first is the low (356°C) melting point and low decomposition temperature of the oxidizer. Soon after melting, KCIO 3 decomposes according to equation 3.1. 

The decomposition reaction of potassium chlorate is rare among the common oxidizers because it is exothermic, with a heat of reaction value of approximately -10.5 kcal/mole [ 2]. While most other oxidizers require a net heat input for their decomposition, potassium chlorate dissociates into KCl and O2 with the liberation of heat. This heat output can lead to rate acceleration, and allows the ignition of potassium chlorate-containing compositions with a minimum of external energy input (ignition stimulus). 

FIG. 5.5 Thermogram of pure potassium chlorate, KCIO thermal events are observed prior to the melting point (356°Q. Exothermic decomposition occurs above the melting point as oxygen gas is liberated. 

Therefore, the initial choice for an oxidizer is one with an exothermic heat of decomposition such as potassium chlorate (KCIO 3). However, mixtures of both chlorate and perchlorate salts with active metal fuels are too ignition-sensitive for commercial use, and the less-reactive - but safer - nitrate compormds are usually selected. Potassium perchlorate is used with aluminum and magnesium in some "photoflash" mixtures these are extremely reactive compositions, with velocities in the explosive range. 

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