Sulphuric acid shapes

Use the apparatus shown in Fig. 38, p. 63, using a thermometer reading to 100° and with water running through the vertical condenser. Place in the 25 ml. pear-shaped flask 5 ml. of ethanol, 5 ml. of glacial acetic acid and add carefully with shying i ml. of concentrated sulphuric acid. Attach the flask to the reflux condenser and boil the mixture gently for 10 minutes. 

The conclusion that the nitration of quinoline in sulphuric acid takes place via the conjugate acid has been confirmed by Moodie et al.50, who measured the rates of nitration of a wide range of heterocyclic compounds in nitric acid-sulphuric acid mixtures at a range of temperatures. A summary of the second-order rate coefficients and Arrhenius parameters is given in Table 4. From an analysis of the shapes of the plots of log k2 versus sulphuric acid acidity (or some function of this), it was concluded that all of the compounds starred in Table 4... 

Many variations of the shape of steel drills for glass have been described— from Faraday who used the ground end of a triangular file to C. V. Boys who designed a special drill of tool steel—while other workers (B. Brown, 1927 N. G. Heatley, 1938) advocate the use of a normal twist drill. These drills are used in conjunction with some lubricant—usually the traditional camphor in turpentine, although pure turpentine or other mobile liquid seems to be as good, while Heatley states that dilute sulphuric acid is effective. To avoid splintering, the hole should be drilled from both sides. 

Lyotropic polymeric LC, formed by dissolving two aromatic polyamides in concentrated sulphuric acid, have been studied using variable-director 13C NMR experiments.324 The experimental line shapes at different angles w.r.t the external field were used to extract macromolecular order and dynamic in these ordered fluids. An interesting application of lyotropic LC is for the chiral discrimination of R- and S-enantiomers, and has recently been demonstrated by Courtieu and co-workers.325 The idea was to include a chiral compound 1-deutero-l-phenylethanol in a chiral cage (e.g., /1-cyclodextrin) which was dissolved and oriented by the nematic mean field in a cromolyn-water system. Proton-decoupled 2H NMR spectrum clearly showed the quad-rupolar splittings of the R- and S-enantiomers. The technique is applicable to water-soluble solutes. 

Figure 3. The five variants of size and shape of sulphuric acid catalysts from Haldor Topsoe.

The catalyst activity depends not only on the chemical composition but also on the diffusion properties of the catalyst material and on the size and shape of the catalyst pellets because transport limitations through the gas boundary layer around the pellets and through the porous material reduce the overall reaction rate. The influence of gas film restrictions, which depends on the pellet size and gas velocity, is usually low in sulphuric acid converters. The effective diffusivity in the catalyst depends on the porosity, the pore size distribution, and the tortuosity of the pore system. It may be improved in the design of the carrier by e.g. increasing the porosity or the pore size, but usually such improvements will also lead to a reduction of mechanical strength. The effect of transport restrictions is normally expressed as an effectiveness factor q defined as the ratio between observed reaction rate for a catalyst pellet and the intrinsic reaction rate, i.e. the hypothetical reaction rate if bulk or surface conditions (temperature, pressure, concentrations) prevailed throughout the pellet [11], For particles with the same intrinsic reaction rate and the same pore system, the surface effectiveness factor only depends on an equivalent particle diameter given by... 

Bro mo-pentammino-iridium Sulphate, [Ir(NH3)5Br]SO4.H20, is produced by triturating the nitrite with excess of sulphuric acid. On the addition of water slender needle-shaped crystals separate on cooling. They appear to be the acid sulphate, but are converted into the normal salt by redissolving in water and precipitating with alcohol. The substance crystallises in shining yellowish plates which lose their water of hydration at 100° C-.1... 

The sulphate, [Ir(NH3)4(NO2)2]2SO4. H20, is obtained by decomposing the chloride with potassium sulphate or sulphuric acid. On cooling the solution needle-shaped crystals separate. It is somewhat sparingly soluble in both hot and cold water, but dissolves on the addition of a small quantity of sulphuric acid. With large quantities of sulphuric acid an acid salt is formed. 

Reduction of a Metal Oxide wear eye protection ). Assemble the apparatus shown in Fig. 44 and check its tightness. Put 40-50 pieces of granulated zinc into a 250-ml flask. Pour anhydrous calcium chloride into U-shaped tube. Put 0.3 g of copper oxide into the wide part of a refractory tube, and a piece of copper gauze or foil (why ) into the gas-discharge tube out of which hydrogen will flow. Pour 100-150 ml of a 20% sulphuric acid solution into the flask. Again check... 

The viscosity isotherms for 25°C are shown in Fig. 1 and in Tables 1-5. The viscosity of the system sulphuric acid-nitromethane decreases constantly from sulphuric acid to nitromethane. Its shape is characteristic of systems in which no addition compounds or addition compounds of low stability are formed and one of the components is associated. The viscosity isotherm of the system with nitrobenzene has the known S-shape, i.e. the isotherm has an inflection point and no maximum. Finally, the viscosity isotherms of the systems with o-, m-and p-nitrotoluene have maxima at about 90 mole % of sulphuric acid and the viscosity values increase in the order o-, m- and p-derivative. 

But sulphurous acid as nearly pure as possible, in fac quite pure, if made to traverse a little water to take up any sulphuric aoid, may be obtained by heating sulphuric acid with one-third its weight of copper, in the shape of turninge or clippings. One atom of copper takeB up one atom of oxygen from one atom of sulphuric acid, and becomes oxide of copper, which itself immediately combines with another equivalent of sulphuric acid, forming sulphate of copper— ... 

Sulphurous acid, in the shape of sulphite of soda, has. been an article of commerce for some time, under... 

A recuperative bayonet sulphuric acid decomposition reactor has been designed by researchers at Sandia National Laboratories (SNL) that features all-silicon carbide (SiC) construction for the heated parts, can be made from readily available SiC shapes, makes the most use of heat recuperation, and has all of its fluid connections at sufficiently low temperatures that conventional seal materials can be used. Bench-scale experiments using electric resistance heaters as the energy source have verified that the design functions as intended. 

The addition of sulphuric acid to a solution of either a chromate or a dichromate liberates chromic acid which is very soluble and can exist in solution in the different forms, H CrCh, H C Cb and Cr03, in equilibrium with each other. With the addition of a large excess of concentrated H2SO4, water is withdrawn from the hydrated forms and the anhydride separates in the shape of red needles. 

The cast iron muffle was replaced by a fireclay brick muffle. The arch was made of carborundum which conducted heat well and withstood the effect of sulphuric acid. The outer brickwork was circular in shape and not rectangular as in the Mannheim furnace. Consequently, the surface area of the muffle was smaller so that the loss of heat due to radiation was reduced to a minimum. The interchangeable blades on the four arms of the stirring device, which revolved at a velocity of 1 to 2 r. p. m., were made of carborundum which resists to wear and does not pollute the product either with iron or chromium. This is of great importance when manufacturing sulphate for glass works. 

Tri-nickel Tetrasulphide, Ni3S4, results when metallic nickel is heated either with sulphurous acid or a solution of nickel sulphite to 200° C. under pressure.3 Its existence as a separate chemical entity is indicated by the shape of the freezing-point curves of nickel sulphides.4... 

It is easy to demonstrate that electrolysis is always accompanied by the transport of material in an electrolysis cell. If for example the blue solution of copper sulphate and the orange solution of potassium dichromate are mixed in equimolar concentrations, a brownish solution is obtained. This solution can be placed in a U-shaped electrolysis cell and topped up with a colourless layer of dilute sulphuric acid on each side (Fig. 1.2). If this solution is then electrolysed, the hitherto colourless solution next to the cathode slowly becomes blue, while... 

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