Subject mercuric halides

The structure of mercuric halides dissolved in aromatic solvents continues to be the subject of controversy. Careful vapour pressure osmometric studies153,154 now show conclusively that there is considerable self-association of mercuric halides in their solutions in benzene, toluene, xylene, and mesitylene. The association was found to be dimeric for chloride and bromide, and dimeric and possibly trimeric for iodide. 

Sodium reacts with explosive violence when mixed with mineral acids, especially hydrofluoric, sulfuric, and hydrochloric acids. It bums spontaneously in fluorine, chlorine, and bromine and a luminous reaction occurs with iodine. Sodium added to liquid bromine can explode when subjected to shock (Mel-lor 1946). Violent explosions may result when a mixture of sodium and a metal halide is subjected to impact. Shock-sensitive mixtures are formed upon combination with halogenated hydrocarbons, such as methyl chloride, methylene chloride, or chloroform. It reacts with incandescence when combined with many metal oxides, such as lead oxide or mercurous oxide. 

Nickel is not subject to stress corrosion cracking in any of the chloride salts and it exhibits excellent general resistance to nonoxidizing halides. Oxidizing acid chlorides such as ferric, cupric, and mercuric are very corrosive and should be avoided. 

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