Manganate , silver

Manganic Fluoride, MnFg, mw 111.94, red, poisonous crysts, sp gr 3-54 mp — decomp on heating sol in acids decomp by w. Can be prepd by dissolving Mn in dil HF contd in a silver basin (Ref 2) and by other methods. Used as a Guorinating agent Refs 1) Gmelin-Kraut, not found 2) Mellor 12(1932), 342 3) CondChemDict (1961),... 

The oxidation of aromatic hydroxylamines with peracids in the presence of cupric ions produces nitroso compounds. In the rigorous absence of metallic ions, azoxy compounds are formed [32]. On the other hand, the air oxidation is strongly accelerated by metals, the approximate order of activity based on a kinetic study being cupric s ferric > manganous > nickel chromic > cobaltous ions. Silver and stannous ions appear to have no effect [33]. 

Although metal ions do not catalyze the decarboxylation of monocarboxylic acids in solution, a variety of metal ions catalyze the decarboxylation of oxaloacetic acid anion, leading to the formation of pyruvic acid (27). The metal ions involved were cupric, zinc, magnesium, aluminum, ferric, ferrous, manganous, and cadmium, approximately 10-2 to 10-3 M (27). Of these, the aluminum, ferric, ferrous, and cupric ions were the most efficient sodium, potassium, and silver ions were inactive. This process involves the decarboxylation of a / -keto acid, which undergoes a relatively facile uncatalyzed decarboxylation. However, not every decarboxylation of a / -keto acid is catalyzed by metal ions—only those... 

Pour a small amount of copper sulphate, silver nitrate, and potassium manganate solutions into three beakers and drop a small piece of white phosphorus into each of them. In 10 or 15 minutes, extract the phosphorus from the solutions. Dry it as indicated above, put it on an iron plate, and heat it. What happens How do the given salts affect white phosphorus How can the different activity of white and red phosphorus be explained Write the equations of [the [reactions. 

In aqueous solution, manganous salts are oxidised to manganese dioxide,6 and if silver nitrate is present as catalyst, to permanganate 0 the latter change constitutes Marshall s reaction. Chromium solutions in a similar manner give rise to chromate,7 even without a catalyst. Ferrous and cerous salts are converted into ferric and ceric salts, respectively, and phosphites are oxidised to phosphates. 

Formic acid solution reacts as follows 11) with hydroxides, oxides, carbonates, to form formates, e g., sodium formate, calcium formate, and with alcohols to form eslers (2) with silver of ammonio-silver nitrate to form metallic silver (3) with ferric formate solution, upon heating, to form red precipitalc of basic ferric formate (4) with mercuric chloride solution to form mercurous chloride, white precipitate and (SI with permanganate lin the presence of dilute H-SOj) to form CO and manganous salt solution. Formic acid causes painful wounds when it ennies in contact with the skin. At IhO C. formic acid yields CO plus H . When sodium formate is heated in vacuum at 300°C. H- and sodium oxalate are formed. With concentrated ll.SOj heated, sodium formate, or other formate, or formic aeid. yields carbon monoxide gas plus water. Sodium formate is made by healing NaOH and carbon monoxide under pressure at 2I0 C. 

Hyposulfurous acid is a powerful reducing agent, e.g., with copper sulfate forms cuprous hydride Cu H , brown precipitate, which evolves hydrogen gas and leaves copper on warning, with silver nitrate yields finely divided silver, with permanganate yields manganous compounds. Hyposulfurous acid is formed by reaction of sodium hyposuliile and an acid. 

Other typical reagents generated for coulometric titrations are hydrogen and hydroxyl ions, redox reagents such as ceric, cuprous, ferrous, chromate, ferric, manganic, stannous, and titanous ions, precipitation reagents such as silver, mercurous, mercuric, and sulfate ions, and complex-formation reagents such as cyanide ion and EDTA [8-10]. 

E. P. Alvarez 2 found that the pemitrates react with soln. of lead acetate (white precipitate), silver nitrate (white precipitate), mercurous nitrate (white precipitate with rapid decomposition), mercuric chloride (red precipitate), copper sulphate (blue precipitate), zinc and cadmium sulphates (white precipitate), bismuth nitrate (white precipitate), gold chloride (slight effervescence and escape of oxygen), manganous chloride (pink precipitate), nickelous chloride or sulphate (greenish-white precipitate), cobaltous nitrate and chloride (pink precipitate), ferrous sulphate (green or bluish-green precipitate), ferric chloride (red ferric hydroxide), and alkaline earth chlorides (white precipitates). The precipitates are all per-salts of the bases in question. 

Nitrates, chlorates, acetates, manganates, and permanganates are all soluble exceptions are a few basic nitrates (e.g. Bi and Sb) and basic acetates (e.g. Fe) silver and mercury(I) acetates are sparingly soluble. 

The selective oxidation of diols in which one or both hydroxy groups are allylic has been reported on a number of occasions. Reagents which have proved use for this include silver carbonate on Celite, barium manganate/ and manganese dioxide, as illustrated in equations (29)-(31). 

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