Manganese II ion

Manganate(VII) is reduced to manganese(II) ion in acid solution (usually sulphuric acid) ... 

Permanganate is inherently unstable in the presence of manganese(II) ions 2Mn04 + 3Mn2+ +2H20 = 5Mn02 + 4H +... 

The method is based upon the titration of manganese) II) ions with permanganate in neutral pyrophosphate solution ... 

You decide to use sulfide precipitation to separate the copper(II) ions from the manganese(II) ions in a solution that is 0.20 m Cu2+(aq) and 0.20 m Mn2+(aq). Determine the minimum sulfide ion concentration that will result in the precipitation of one cation (identify the cation) hut not the other. 

Permanganate ions, Mn04, react with oxalic acid, H2C204, in acidic aqueous solution, producing manganese(II) ions and carbon dioxide. The skeletal equation is... 

Self-Test 12.1B Acidified potassium permanganate solution reacts with sulfurous acid, H2SO. (aq), to form sulfuric acid and manganese(II) ions. Write the net ionic equation for the reaction. In acidic aqueous solution, H2S03 is present as electrically neutral molecules and sulfuric acid is present as HS04 ions. 

Self-Tfst 4B Write the diagram for a cell that has an electrode consisting of a manganese wire dipping into a solution of manganese(II) ions on the left, a salt bridge, and a coppcr(II)/copper(I) electrode on the right with a platinum wire. 

In the presence of manganese(II) ions the rate of oxidation of H2R by chromic acid decreases . Under favourable experimental conditions (high concentration of alcohol and low concentration of chromate) the diminution of rate is about 50 % which is in accordance with results listed in Table 6, according to which ci = 0.5. The inhibiting effect of manganese(II) on the oxidation of H2R can be explained by reaction (23) followed by step (24). Therefore the induced oxidation of manganese(II) can be described by reactions (26), (23) and (24). 

To decide whether the reaction involves 1- or 2-electron transfers, i.e. chromium-(rv) or chromium(V) is formed first, the induced oxidation of manganese(II) was investigated. When sodium perchlorate was used to maintain a constant ionic strength, the rate of oxidation of benzaldehyde dropped to one-half of the original rate in the presence of manganese(II) ions. On the contrary, when magnesium perchlorate was used as the neutral salt, the rate was reduced to of its original value. This peculiar observation, however, has not been interpreted. 

Heterocyclic nitrogen donors and their adducts with zinc chloride have been studied.623,624 A large number of other ligand systems have also been characterized, for example, zinc halide adducts of 2,2-dimethylpropane-1,3-diamine and hexamethylphosphoramide have been studied.625,626 The formation of mixed ligand complexes with chloride and substituted pyridines has been studied.627 The zinc tris(pyridyl) chloride anion has also been structurally characterized.628 Manganese(II) ions have been used to probe the stereochemistry in reactions of zinc halides with pyrazine.629... 

Unfortunately, oxidation of chloride ions = 1l3 will also occur. This problem is overcome by using the Zimmerman-Rheinhardf reagent which contains manganese(II) ions and phosphoric acid. 

Manganese halides, 15 573-574 Manganese heptoxide, 15 597 Manganese hydroxide, 15 575 Manganese(II) ion, complexes containing, 15 573... 

In acid solution, the manganate(VII) ion is reduced to the manganese(II) ion with decolorisation ... 

Write a balanced half-reaction that shows the reduction of permanganate ions, Mn04, to manganese(II) ions in an acidic solution. 

A galvanic cell involves the overall reaction of iodide ions with acidified permanganate ions to form manganese(II) ions and iodine. The salt bridge contains potassium nitrate. 

Metal-ion catalysis has been extensively reviewed (Martell, 1968 Bender, 1971). It appears that metal ions will not affect ester hydrolysis reactions unless there is a second co-ordination site in the molecule in addition to the carbonyl group. Hence, hydrolysis of the usual types of esters is not catadysed by metal ions, but hydrolysis of amino-acid esters is subject to catalysis, presumably by polarization of the carbonyl group (KroU, 1952). Cobalt (II), copper (II), and manganese (II) ions promote hydrolysis of glycine ethyl ester at pH 7-3-7-9 and 25°, conditions under which it is otherwise quite stable (Kroll, 1952). The rate constants have maximum values when the ratio of metal ion to ester concentration is unity. Consequently, the most active species is a 1 1 complex. The rate constant increases with the ability of the metal ion to complex with 2unines. The scheme of equation (30) was postulated. The rate of hydrolysis of glycine ethyl... 

The structure of Helvite, Mn CBeSiOJjS, has been reported. The tetrahedral manganese ii) ions are bonded to one sulphur and three oxygen atoms. M2Mn3S4 (M = Rb or Cs) have been prepared by reactions in the molten state under nitrogen. An X-ray study on the caesium compound showed the manganese and caesium atoms to be arranged in layers separated by layers of sulphur atoms. ... 

A series of complexes have been reported of type [Mn2L(R C0A]C104, where LH2 is (211) (with R = OMe, H, F, Br for R = Me and R = Br for R = CF3). The electrochemical redox chemistry of these species was shown to be effectively controlled by the nature of R and R. The X-ray structure of the derivative with R = R = Me shows that each manganese(II) ion has a highly distorted octahedral geometry. 

---