Hydrogen over mercury

Hydrocarbon A has the formula C9HI2 and absorbs 3 equivalents of H to yield B, C9H]g, when hydrogenated over a Pd/C catalyst. On treatment of A with aqueous H2S04 in the presence of mercury(d), two isomeric ketones, C and D, are produced. Oxidation of A with KMn04 gives a mixture of acetic acid (CH3C02H) and the tricarboxylic acid E. Propose structures for compounds A-D, and write the reactions. 

Trigeminal trihalides are completely reduced by catalytic hydrogenation over palladium [62] and Raney nickel [63], and partially reduced to dihalides or monohalides by electrolysis using mercury cathode [57 ], by aluminum... 

Although many historians of chemical progress mention Cavendish as the discoverer of hydrogen, he himself made no such claim and prefaced his remarks on the explosibility of a mixture of hydrogen and air with the words,. . it has been observed by others.. . He was, however, the first to collect gases over mercury (41) and distinguish hydrogen... 

Numerous methods for the synthesis of salicyl alcohol exist. These involve the reduction of salicylaldehyde or of salicylic acid and its derivatives. The alcohol can be prepared in almost theoretical yield by the reduction of salicylaldehyde with sodium amalgam, sodium borohydride, or lithium aluminum hydride by catalytic hydrogenation over platinum black or Raney nickel or by hydrogenation over platinum and ferrous chloride in alcohol. The electrolytic reduction of salicylaldehyde in sodium bicarbonate solution at a mercury cathode with carbon dioxide passed into the mixture also yields saligenin. It is formed by the electrolytic reduction at lead electrodes of salicylic acids in aqueous alcoholic solution or sodium salicylate in the presence of boric acid and sodium sulfate. Salicylamide in aqueous alcohol solution acidified with acetic acid is reduced to salicyl alcohol by sodium amalgam in 63% yield. Salicyl alcohol forms along with -hydroxybenzyl alcohol by the action of formaldehyde on phenol in the presence of sodium hydroxide or calcium oxide. High yields of salicyl alcohol from phenol and formaldehyde in the presence of a molar equivalent of ether additives have been reported (60). Phenyl metaborate prepared from phenol and boric acid yields salicyl alcohol after treatment with formaldehyde and hydrolysis (61). 

Mercury is a very widely used electrode material for studying cathodic processes owing to its very high hydrogen over-potential however, its anodic range is small. For use in dropping electrodes, mercury purity is most important. Its purification has been described extensively and is in four parts. 

Excess methylmagnesium iodide and 0.1776 g of Compound A (formula C4H10O3) react to give 84.1 ml of methane collected over mercury at 740 mm and 25°. How many acidic hydrogens does Compound A possess per molecule Suggest a possible structure on the basis that spectral data indicate (a) there is no C=0 group in the molecule and (b) A is achiral. 

Catalytic conversions were experimentally studied in Russia toward the end of the nineteenth century, and especially in the twentieth century, and regularities were empirically established in a number of cases. The work of A. M. Butlerov (1878) on polymerization of olefins with sulfuric acid and boron trifluoride, hydration of acetylene to acetaldehyde over mercury salts by M. G. Kucherov (1881) and a number of catalytic reactions described by V. N. Ipatieff beginning with the turn of the century (139b) are widely known examples. S. V. Lebedev studied hydrogenation of olefins and polymerization of diolefins during the period 1908-13. Soon after World War I he developed a process for the conversion of ethanol to butadiene which is commercially used in Russia. This process has been cited as the first example of commercial application of a double catalyst. Lebedev also developed a method for the polymerization of butadiene to synthetic rubber over sodium as a catalyst. Other Russian chemists (I. A. Kondakov I. Ostromyslenskif) were previously or simultaneously active in rubber synthesis. Lebedev s students are now continuing research on catalytic formation of dienes. 

The source of most of the hydrogen chloride manufactured on a la.rge or small Scale is one of the common chlorides. In the laboratory the gas is usually prepared by heating a mixture of sulphuric acid and sodium chloride the gas can be dried by calcium chloride or cone, sulphuric acid, Fig. 9, and collected over mercury, or... 

Stephen Touhnin rejected the positivist-Whig notion of instant rationality according to which, in 1775, Lavoisier used the crucial experiment on the calcination and revivification of mercury by heat alone to discredit the phlogiston theory and establish the oxygen theory. As Toulmin noted, Priesdey responded to this experiment in 1783 with a crucial experiment of his own. Priestley appealed to the reaction between minium (lead oxide) and inflammable air (hydrogen) over water as a counter demonstration , in which the phlogiston... 

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