Decomposition of potassium chlorate

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. 

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. 

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. 

I) Decomposition of potassium chlorate in the presence of solid Mn02 Mn02... 

The composition and constitution of perchloric acid.—The composition of perchloric acid was established by F. von Stadion,80 and verified by J. L. Gay Lussac by the decomposition of potassium chlorate. 10 03 grams of perchloric acid were dissolved in water, and treated with a small excess of potassium carbonate. The soln. was evaporated to dryness with a slight excess of acetic acid, and washed with absolute alcohol to remove the potassium acetate. The residual potassium perchlorate was dried and weighed. The potassium perchlorate was ignited to drive off the oxygen. The results were ... 

Reaction rates are affected not only by reactant concentrations and temperature but also by the presence of catalysts. A catalyst is a substance that increases the rate of a reaction without being consumed in the reaction. An example is manganese dioxide, a black powder that speeds up the thermal decomposition of potassium chlorate ... 

The decomposition of potassium chlorate (KC103) is catalysed by manganese dioxide (Mn02). 

Qualitative and quantitative analysis show that a catalyst undergoes no change in mass or chemical composition. However, it may undergo a physical change. Thus, granular manganese dioxide (Mn02) used as a catalyst in the thermal decomposition of potassium chlorate is left as a fine powder at the end of the reaction. 

This decomposition of potassium chlorate is a fairly common way to generate oxygen gas in the laboratory. The catalyst, written above the arrow, greatly facilitates this process. 

It assists catalytically the conversion of sodium chloride into sodium sulphate when heated in a current of air along with finely divided pyrites.4 It also accelerates the decomposition of potassium chlorate when heated with this salt, much in the same way as manganese dioxide has long been known to do. More chlorine is evolved during the decomposition, however, and under certain conditions the oxygen is evolved at an even lower temperature than when manganese dioxide is used.5... 

That only the beginning and end of reactions are represented. Thus, in Exp. 9, certain compounds are formed and decomposed again as the temperature increases but these facts do not appear in the equation, because here we are concerned not with phases, but only with the actual ultimate decomposition of potassium chlorate into oxygen and potassium chloride. 

To answer the second question let us calculate the theoretical yield of oxygen from 2.00 g of potassium chlorate. The equation for the decomposition of potassium chlorate is... 

When the reactants and the catalyst are in the same physical state the catalyst is called a homogeneous catalyst e.g. concentrated sulfuric acid speeds up the reaction between ethanoic acid and ethanol to form the ester, ethyl ethanoate. Manganese(IV) oxide catalyses the thermal decomposition of potassium chlorate(V) to give oxygen. 

What mole ratios can be written for the decomposition of potassium chlorate (KCIO3) This reaction is sometimes used to obtain small amounts of oxygen in the laboratory. 

The value of i p is 27 for the thermal decomposition of potassium chlorate at a given high temperature. What is the partial pressure of oxygen in a closed container in which the following system is at equilibrium at the given temperature (This can be a dangerous reaction.)... 

The catalyst is the same phase as the reactants and products. Examples are hydrolysis of esters by acids (liquid-liquid), oxidation of SOi by NO (vapor-vapor), and decomposition of potassium chlorate by MnOi (solid-solid). Usually, the liquid phase is most common, with both catalyst and reactants in solution. 

Oxygen can be produced in a free, undiluted state by the decomposition of potassium chlorate (KC103). The decomposition is brought about merely by breaking it up into potassium chloride and oxygen. The arrangement of the apparatus necessary to carry out the... 

A common laboratory preparation of oxygen gas is the thermal decomposition of potassium chlorate (KCIO3). Assuming complete decomposition, calculate the number of grams of O2 gas that can be obtained from 46.0 g of KCIO3. (The products are KCl and O2.)... 

IV. —Reactions of the fourth order. These are comparatively rare. The reaction between hydrobromic and bromic acids is, under certain conditions, of the fourth order. So is the reaction between chromic and phosphorous acids the action of bromine upon benzene and the decomposition of potassium chlorate. The general equation for an rc-molecular reaction, or a reaction of the wth order is... 

---