Mixture without condensation

In the process of manufacturing, the major problems appear to be the same as has been met in the field transferring of natural gas mixtures without condensation, separation of heavy hydrocarbons, and pressure and temperature changes which occur inside of the sample system. 

Salicylanilide (m.p. 131-132°) is obtained by heating the mixture without a diluent for 3 hours at 180-200° with a short air condenser, pouring the melt into 100 ml. of alcohol and working up as above. The persistent pink color is not easily removed. 

Eq. (2.3) shows that when using gas ballast (B 0) vapors can also be pumped without condensation if no gas is present at the intake of the pump. The gas ballast may also be a mixture of non-condensable gas and condensable vapor as long as the partial pressure of this vapor... 

Suppose, for instance, that a mixture of volatile liquids is in the presence of the mixed vapor which it emits at the temperature T and pressure it the liquid mixture and the mixed vapor which remain in equilibrium have definite compositions if the liquid mixture and the mixed vapor happen to have the same composition at a certain temperature and pressure, the equilibrium of the system for this temperature and pressure is evidently indifferent it is in fact clear that, without changing the composition of any of the phases, consequently without disturbing the equilibrium of the system, we may either vaporize a part of the liquid mixture or condense a part of the mixed vapor. 

The method of sudden cooling seems to be the only one which may be applied to the study of the dissociation of a gas which is formed without condensation from its gaseous elements but in the case where the gas which dissociates is formed from its gaseous elements with condensation, every decomposition of this gas has for effect the decrease of the density with respect to air of the gaseous mixture where it exists in presence of gases coming from its decomposition the study of the variations undergone by the density referred to air of this mixture when the temperature and pressure are varied, when an excess of one or the other component is introduced into the system, furnishes, on the subject of the dissociation of the compound considered, indirect but exact information... 

The molybdenum hexacarbonyl complex has recently been introduced as a condensed source of carbon monoxide for small-scale carbonylation chemistry [150]. This easily handled and inexpensive solid delivers a fixed amount of carbon monoxide on heating or on addition of a competing molybdenum ligand (for example DBU). This enables direct liberation of carbon monoxide in the reaction mixture without the need for external devices. 

Polymerizations were conducted, as shown in Scheme 2, by condensing the dialdehydes with p-phenylene diamine under toluene reflux, in which the water formed was removed out of the polymerization system. One monomer Cg-M was additionally polymerized by condensation in hexamethyl phosphoramide(HMPA)/N-methyl pyrrolidone(NMP) mixture without removing the water. Polymerization yields were practically quantitative. 

A similar reaction of ethyl levulinate was conducted with a UF preparation. The acid-catalyzed reaction incorporated the levulinate into the resin structure, forming aii insoluble mass. This reaction does not occur to a large extent during the initial particle board degradation owing to the large volume of ethanol solvent however, it can cause a problem in the workup of the products after the ethanol has been removed. The reaction explains the failure of attempts to distill ethyl levulinate directly from the levulinate-resin product mixture without prior extraction of the ester from the resin. These attempts resulted in low ester yields and the formation of intractable resin. Thus, by extracting the ester we can avoid the inadvertent condensation reaction with the resin. 

As a typical example, pressure profiles for a CO -air mixture with 75 mole per cent CO are given in Fig.2. The upper diagram shows an expansion without condensation, employed to determine the effective nozzle profile, whereas the lower diagrams indicate the deviation of the static pressure downstream of the Wilson point. 

Fig.2. Typical pressure profiles of two expansions of a CO -air mixture without and with spontaneous condensation...

In PV, the liquid mixture to be separated (feed) is placed in contact with one side of a membrane and the permeated product (permeate) is removed as a low-pressure vapor from the other side. The permeate vapor can be condensed and collected or released as desired. The chemical potential gradient across the membrane is the driving force for the mass transport. The driving force can be created by applying either a vacuum pump or an inert purge (normally air or steam) on the permeate side to maintain the permeate vapor pressure lower than the partial pressure of the feed liquid. Vacuum PV, which is customarily referred to as the standard PV, is the most widely utilized mode of operation, while inert purge PV is normally of interest if the permeate can be discharged without condensation. In addition to these two... 

Majumdar and coworkers [83] synthesized fused thiopyran derivatives 150 in 83-98% yields through a three-component domino reaction of 71a, 69, and indoline-2-thione 136 or 4-hydroxy-2H-thiochromene-2-thione in water at 100 °C (Scheme 12.59). The resulting heterocyclic products could be conveniently separated from the reaction mixture without the use of any volatile organic solvent. In the reaction, three new bonds and one stereocenter were formed. When indoline-2-thione was replaced with sodium azide 151, the three-component domino reaction provided 5-substituted-tetrazoles 152 in 67-88% yields through a Knoevenagel condensation/1,3 dipolar cycloaddition sequence (Scheme 12.60) [84]. 

Water vapor does not condense onto the films By exposing the films to an environment with controlled humidity, Sprenger et al. [58] demonstrated that during spin-coating it is possible to control the phase morphology of a polymer mixture without varying the composition of the films. 

Mono-tosylated-3-CD was prepared in an alkaline aqueous solution in the same manner as described in reference 4. This compound is identical in all respects with C-6 mono-tosylated-3-CD [5]. lodination of mono-tosylated-3-CD (20 g) with sodium iodide (24 g) was carried out in methanol (300 ml) at 70 C for 50 hours. After reprecipitation with acetone, 3-CD-iodide was purified by a column of highly porous polystyrene gel (D lAION HP-20). The purity was confirmed by HPLC. 3-CD-iodide (10 g) and free histamine (9.1 g) were added to DMF (400 ml), and the solution was kept at 100 °C for 24 hours. The reaction mixture was condensed and dissolved in water and applied to a column of HP-20. The column was eluted with water and 20% aqueous methanol. The methanolic eluate was evaporated to dryness and the dried material was dissolved in water and applied to a column of silica gel (WAKOGEL C-100). The column was eluted with water and 5% aqueous sodium carbonate. The sodium carbonate eluate was again applied to a column of HP-20. Water and 20% aqueous methanol were used to eluate. The methanolic eluate was evaporated to dryness to give the 3-CD-histamine. The purity of the product was confirmed by HPLC (Waters, Radial-PAK Cartridge C-8, solvent acetonitrile-water system). Yield 8 v l0%. Anal.Calc.for C47H77034N3 H20 C,45.26 H,6.34 N,3.37. Found C,45.13 H,6.20 N,3.26. All reagents were purchased from commercial suppliers and were used without further purification. 

The process is carried out as follows A mixture of 20 c.c. of lemon oil, 20 c.c. of 90 per cent, alcohol, 20 c.c. of a 5 per cent, solution of hydroxylamine hydrochloride in 80 per cent, alcohol, and 8 c.c. of normal alcoholic potash solution is gently boiled for thirty minutes under a reflux condenser. A similar mixture, without the lemon oil, is treated in exactly the same manner. After cooling, the condensers are washed down with water to restore any traces of hydroxylamine to their respective flasks, and the contents of the flasks duuted with about 200 c.c. of water. A few drops of phenolphthalein are added to the flasks, and the contents first neutralised with semi-normal alkali. The hydroxylamine is now titrated with semi-normal sulphuric acid solution, using methyl orange as indicator. A few drops of the indicator should be added to the flask, so that a general indication of the approach of the end reaction is given, but the end reaction itself should bie observed by the familiar process of spotting on a white tile, on drops of the indicator. Each cubic centimetre of half-normal acid used in the blank experiment, over that used in the assay experiment, is equivalent to 0 076 grm. of citral. 

Transfer a suitable weight of sample (catalysts and sulfuric acid absent) and 5 ml of pure hydriodic acid (AnalaR about 55%) to a clean Kjeldahl flask with B19 quickfit socket. Warm gently and introduce 50 mg pure red phosphorus and some porous pot. Reflux for 45 minutes and then dilute with 5 ml water. Add 5 ml concentrated sulfuric acid and mix. Boil the mixture rapidly (without condenser) to remove hydriodic acid and iodine vapour. If iodine is not completely removed add a further 5 ml of water and boil again until the mixture fumes. Carry out an identical reagent blank omitting only the sample additions. Add a suitable quantity of Kjeldahl digestion catalysts A or B (Table 2.8), concentrated sulfuric acid and 0.05 g glucose (note 3) to the reduced sample and blank solutions. 

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