Sulfuric acid monohydrate

All current industrial production of acrylamide is believed to be by saponification of acrylonitrile [1,2]. Until recently, the saponification of acrylonitrile was done exclusively with sulfuric acid monohydrate. 

The end point corresponded to generation of sulfuric acid monohydrate the experimenter subsequently adopted the rules of thumb that oxidative side reactions do not occur while the availability of water is less than this, and that dinitration side-products are a consequence of charging substrate, traditionally but irrationally, to nitration mixture. 

Sulfuric acid tetrahydrate (SAT) also ultimately freezes out of these ternary solutions (Molina et al., 1993 Iraci et al., 1995). At higher temperatures found at higher altitudes in the middle and low latitudes, sulfuric acid monohydrate (SAM) may also be stable (Zhang et al., 1995). 

Adequate description of both the equilibrium geometry and vibrational spectra is critically important for the free energy calculations. Table 21.1 presents a comparison of equilibrium geometries of sulfuric acid monohydrate obtained at different levels of theory with experimental data of Leopold with co-authors [118]. As maybe seen from Table 21.1, both ab initio and DFT methods reproduce the hydrate structure with sufficient accuracy. The PW91PW91 and MP2 in combination 6-311-1—l-G(3df,3pd) basis set provide the best overall agreement with experimental data. 

Finely powdered hydrobenzamide (350 g) is added in portions to sulfuric acid monohydrate (1650 g) at 10-12°. When dissolution is complete the mixture is cooled to 0° and treated dropwise with nitrating acid (30% of nitric and 70% of sulfuric acid monohydrate) at such a rate (within 15 h) that the temperature remains below 15°. Then the temperature is allowed to rise to 15-18° during 10-12 h, after which the solution is poured into such a quantity (about 1500 g) of ice that a temperature of 45° is attained. After some hours the cooled solution is filtered and the /n-nitrobenzaldehydeis washed until free from acid. It (450 g) melts at 58° and contains 0.5 % of o-nitro isomer. 

Chlorobenzenedisulfonic acid This is best prepared by heating /7-chlorobenzenesulfonyl chloride and sulfuric acid monohydrate (4 parts) slowly to 160-180°, and then until evolution of hydrogen chloride ceases. The mixture is poured into water and worked up by chalking as described above. 

Naphthalenesulfonic acid 124 Naphthalene, very finely ground (128 g), is added with stirring to sulfuric acid monohydrate (260 g) at 0°. To avoid sudden separation of the sulfonic acid from a supersaturated solution, a seed of the 1-sulfonic add is added after the naphthalene (the seed is obtained by warming a sample of naphthalene in sulfuric add on the water-bath and cooling the product). If the naphthalene has not all been sulfonated, naphthalene will separate when a sample of the reaction mixture is added to watery if that happens the reaction mixture should be warmed for a short time at 60°. 

Occasionally, however, direct sulfonation is applied also to ot-naphthol for instance, 4-hydroxy-l,3-naphthalenedisulfonic acid is obtained as acid sodium salt in 95% yield by means of sulfuric acid at 50° for 2 hours148 or of sulfuric acid monohydrate at 20° for 36-48 hours and then at 40° for a day.149b... 

Fig. 20.6. Above the gas phase structures of sulfuric acid and sulfuric acid monohydrate. Below the structure of the hydrogen snlfate ion in crystaUine (H i0)(HS04) and of the sulfate ion in crystalline (H30)2(S04) 2H2O.

Sulfuric Acid 93 68-140 20-60 E - - plus peanut oil. corn oil. alkyl benzene, sulfuric acid monohydrate. 

The uptake coefficient 3.2 x 10 of this reaction on NAT particle has been recommended by the NASA/JPL panel (Sander et al. 2011) based on the measurement by Hanson and Ravishankara (1991a). The measurement on SAT has not been made and a small value of Yr = 1 x 10 " has been reported for H2S04 H20 (SAM, sulfuric acid monohydrate) by Zhang et al. (1995). The lUPAC subcommittee (Wallington et al. 2012) recommends the upper limit value of Yr < 1 x 10 " based on this value. 

Benzotriazole, allyl alcohol, mercuric acetate, and sulfuric acid monohydrate in benzene stirred and refluxed with azeotropic water-entrainment until water separation ceases after 5 hrs. —> N-allylbenzotriazole. Y 67%. F. e., with lower yields, s. H. Hopff and H. Liissi, Helv. 46, 1052 (1963). 

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