Manganese bromate chlorate

Indications. A blue colour indicates the presence of an oxidising agent such as bromate, chlorate, chromate, dichromate, iodate, lead (IV), manganese (III, IV, VII), nitrate, nitrite, permanganate, or vanadate. 

Lead dioxide Lead perchlorate Lithium chlorate Lithium hypochlorite Lithium perchlorate Lithium peroxide Magnesium bromate Magnesium chlorate Magnesium perchlorate Magnesium peroxide Manganese dioxide Mercurous chlorate Mono-(trichloro)-tetra-(mono-potassium dichloro)-penta-s-triazinetrione... 

Intimate mixtures of chlorates, bromates or iodates of barium, cadmium, calcium, magnesium, potassium, sodium or zinc, with finely divided aluminium, arsenic, copper carbon, phosphorus, sulfur hydrides of alkali- and alkaline earth-metals sulfides of antimony, arsenic, copper or tin metal cyanides, thiocyanates or impure manganese dioxide may react violently or explosively, either spontaneously (especially in presence of moisture) or on initiation by heat, friction, impact, sparks or addition of sulfuric acid [1], Mixtures of sodium or potassium chlorate with sulfur or phosphorus are rated as being exceptionally dangerous on frictional initiation. 

The violence of the explosion is feebler with iodates than it is with chlorates or bromates. The chlorates transform lead oxide to the dioxide manganese oxide in fused alkalies to manganates etc. Ammonium iodate explodes when heated alone. Chloric, bromic, and iodic acids with their salts are energetic oxidizing agents. 

Manganese (II) sulphate test If a bromate solution is treated with a little of a 1 1 mixture of saturated manganese(II) sulphate solution and m sulphuric acid, a transient red colouration (due to manganese(III) ions) is observed. Upon concentrating the solution rapidly, brown, hydrated manganese dioxide separates. The latter is insoluble in dilute sulphuric acid, but dissolves in a mixture of dilute sulphuric and oxalic acids (difference from chlorates and iodates, which neither give the colouration nor yield the brown precipitate). 

To 2 ml of the soda extract add 1 ml concentrated hydrochloric acid and 2 ml of the manganese(II) chloride reagent. A brown (or black) colouration indicates the presence of nitrate, nitrite, hexacyanoferrate(III), chlorate, bromate, iodate, chromate or permanganate. A negative test indicates the absence of the above oxidizing agents except small amounts of nitrates and nitrites and of arsenate if reducing anions have been found, this test is inconclusive. 

When combined with oxidizers such as chlorates, bromates, peroxides, persulfates, and chromium trioxide and subjected to impact, percussion, or heating, powdered zinc explodes. Explosion may result when the powder metal is heated with manganese chloride, hydroxylamine, ammonium nitrate (an oxidizer), potassium nitrate (an oxidizer), sulfur, or interhalogen compounds. Zinc bums in fluorine and chlorine (moist), and reacts with incandescence when mixed with carbon disulfide. 

Chlorates and iodates, under the same conditions, give neither a red color or a precipitate. The test for bromate with manganese sulfate and sulfuric acid may be carried out as a spot reaction, when it is combined with the benzidine reaction for the detection of higher oxides of manganese (page 301). 

This sensitive reaction, which is used for the detection of manganese (see page 300), may also be used to detect periodates. The identification of small amounts of permanganate is accomplished by the use of tetrabase (tetramethyl-/>-diaminodiphenylmethane) a blue quinoidic oxidation product is formed (see page 280). Chlorates, bromates, and iodates do not interfere with the test. Persulfates react with manganese salts, giving... 

Kinetics of the bromide/bromate reaction are discussed in J.Chem.Educ.47 970ym5. The manganese dioxide-catalysed decomposition of potassium chlorate is demonstrated in the same journal (i6iV/.40(1963)78). 

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