Manganese tests

Manganese Test Paper. From a solution of sulphate of manganese turns black by contact with ozone. 

It must also be noted that large amounts of indifferent metallic hydroxides may coat the manganese hydroxide and thereby reduce the sensitivity of the test. For instance, ferric hydroxide, although it has no effect on benzidine, reduces the sensitivity of the manganese test so considerably that instead of 0.15 y (as in pure manganese salts) not less than 2.5 y can be detected in a drop when 250 y iron is also present. If, however, the iron precipitation is prevented by the addition of Rochelle salt, manganese may be detected in the presence even of large amounts of iron. The entire procedure can be accomplished on filter paper. 

To detect manganese in the presence of cerium, which under the normal conditions of the test yields autoxidizable Ce(OH)3, the neutral or weakly acetic acid test solution must first be warmed for 2-3 minutes with a little freshly prepared calcium fluoride. The cerium is precipitated as the insoluble fluoride, and is entrained in the unchanged calcium fluoride. The manganese test can be carried out on the filtrate. 

Aromatic aldehydes react with the dimedone reagent (Section 111,70,2). All aromatic aldehydes (i) reduce ammoniacal silver nitrate solution and (ii) restore the colour of SchifiF s reagent many react with sodium bisulphite solution. They do not, in general, reduce Fehling s solution or Benedict s solution. Unlike aliphatic aldehydes, they usually undergo the Cannizzaro reaction (see Section IV,123) under the influence of sodium hydroxide solution. For full experimental details of the above tests, see under Ali-phalic Aldehydes, Section 111,70. They are easily oxidised by dilute alkaline permanganate solution at the ordinary temperature after removal of the manganese dioxide by sulphur dioxide or by sodium bisulphite, the acid can be obtained by acidification of the solution. 

In 1957, Ethyl Corp. announced anew antiknock compound, methylcyclopentadienyknanganese tricarbonyl [12108-13-3] (MMT). MMT is almost as effective as lead on a per gram of metal basis, but because manganese was more expensive than lead, MMT was not widely used until limits were placed on the lead content of gasoline. MMT was used in unleaded fuel between 1975 and 1978. After a large fleet test suggested that MMT could increase exhaust emissions because it interfered with catalysts and oxygen sensors, EPA banned its use in unleaded fuel in 1978. MMT is used in Canada in unleaded fuel. 

One of the principal advantages of hydrides for hydrogen storage is safety (25). As part of a study to determine the safety of the iron—titanium—manganese metal hydride storage system, tests were conducted in conjunction with the U.S. Army (26). These tests simulated the worst possible conditions resulting from a serious coUision and demonstrated that the metal hydride vessels do not explode. 

The presence of manganese can be detected by formation of the purple MnO upon oxidation using bismuth or periodate in acidic solution. A very sensitive test is the reaction of and formaldoxime hydrochloride in aqueous alkaline solution, which also leads to the production of a purple MnO ... 

Human and animal studies indicate that inorganic manganese compounds have a very low acute toxicity by any route of exposure. The toxicity values for a given Mn compound are shown in Table 20 to depend on the species of test animal as well as the route of exposure. Manganese concentrations as high as 2000 ppm were found to be tolerated by test animals over a six-month period without any ill effects (208). 

European matches, mosdy of brown or black tips, are basically identical with U.S. matches ia their formulations, except that they contain ia addition red iron oxide or manganese dioxide of pigment grade ia the match heads (2). Match materials, testing methods, and related matters have been reviewed (7,8). 

Fig. 7. Performance comparison of "D"-size alkaline—manganese vs carbon-zinc batteries at 21°C on (a) alight drain 150-Q continuous test at 21°C, and...

Fig. 8. Effect of temperature on relative discharge performance of a fresh "D"-si2e battery for service on simulated ratio use, 25- Q 4-h/d test for (a) an alkaline—manganese battery undergoing 260 h of service, and (b) a carbon—2inc battery undergoing 70 h of service (22).

Analysis. Butenes are best characterized by their property of decolorizing both a solution of bromine in carbon tetrachloride and a cold, dilute, neutral permanganate solution (the Baeyer test). A solution of bromine in carbon tetrachloride is red the dihaUde, like the butenes, are colorless. Decoloration of the bromine solution is rapid. In the Baeyer test, a purple color is replaced by brown manganese oxide (a precipitate) and a colorless diol. These tests apply to all alkenes. 

Manganese, copper, iron, cobalt and nickel ions can all initiate oxidation. Untinned copper wire can have a catastrophic effect on natural rubber compounds with which it comes into contact. Inert fillers for use in rubbers are usually tested for traces of such metal ions, particularly copper and manganese. The problem is perhaps less serious in saturated hydrocarbon polymers but still exists. 

Herbsleb, G. and Schwenk, W., Flow Dependence of the Pitting Corrosion of Cr-Ni Steel in NaCl Solution. 2 Tests with Ultrasonics , Werkst. Korros., 24, 267 (1973) C.A., 79, 56638n El Din Shams, A. M., Bodran, M. M. and Khalil, S. E., Corrosion Behaviour of Manganese-containing Stainless Steel. 3 Their Susceptibility Towards Pitting Corrosion , Werkst. Korros., 24, 290 (1973) C.A., 79, 56642j... 

Uranium Short-term tests indicate that the practical upper limit for niobium as a container material for uranium is about 1 400°C . Niobium is dissolved in a uranium-bismuth alloy in less than lOOh at a temperature of 800°C". Uranium eutectics with iron, manganese or nickel, corroded niobium at 800°C and 1 000°C It is significantly attacked by uranium-chromium at 1 000°C . 

Figure 37. Practical test results of a 2CR5 lithium-manganese dioxide battery in a fully automatic camera at 23 °C.

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