Double reaction vessel

This further modification of the diffusion flame technique (see Fig. 5) was used by Polanyi and co-workers [31, 32] in order to prove the formation of free radicals 

of course, necessary for back diffusion of halogen into I to be prevented and for the sodium vapour not to penetrate into II. This technique is of historical interest only. 

---

Fig. 5. Double reaction vessel. Zone I, RBr + Na zone II, R Cl2(l2 ) Reference pp. 236—245...

The contents of a reaction vessel are heated by means of steam at 393 K supplied to a heating coil which is totally immersed in the liquid. When the vessel has a layer of lagging 50 mm thick on its outer surfaces, it takes one hour to heat the liquid from 293 to 373 K. How long will it take if the thickness of lagging is doubled ... 

When 0.52 g of H2 and 0.19 g of 12 are confined to a 750.-mL reaction vessel and heated to 700. K, they react by a second-order process (first order in each reactant), with k = 0.063 L-mol -s 1 in the rate law (for the rate of formation of HI), (a) What is the initial reaction rate (b) By what factor does the reaction rate increase if the concentration of H2 present in the mixture is doubled ... 

The yield is typically 72-78 g. (90-100%). An excess of the reagent is not detrimental to the procedures in Parts B and C. The submitters have doubled the scale of this procedure with no change in the yield. For smaller-scale reactions the submitters recommend that the reagent be purchased from Alfa Division, Ventron Corporation. The checkers used the commercially available reagent successfully in one run, the material having been transferred to the reaction vessel in a dry box. 

St., Newark 5, New Jersey 07105. The lamp was suspended vertieally in a cylindrical, double-walled, Pyrex jacket cooled by flowing water. The inside diameter, outside diameter, and length of the cooling jacket were 3, 4, and 22 cm., respectively. The cooling jacket was clamped in place ca. 5 cm. from the reaction vessel to allow the cooling bath to be raised into position. The use of the 200-W. lamp did not alter the reaction time. 

Here, the sign of equality (=) has been replaced by the double oppositely directed arrows (s=) called a sign of reversibility. Such a reaction is called a reversible reaction. The reversibility of reactions can be detected when both the forward and the reverse reactions occur to a noticeable extent. Generally, such reactions are described as reversible reactions. The most important criterion of a reaction of this type is that none of the reactants will become exhausted. When the reaction is allowed to take place in a closed system from where none of the substances involved in the reaction can escape, one obtains a mixture of the reactants and the products in the reaction vessel. Every reversible reaction, depending on its nature, will after some time reach a stage when the reactants and the products coexist in a state of balance, and their amounts will remain unaltered for unlimited time. Such a state of a chemical reaction is called chemical equilibrium, and the point of such an equilibrium varies only with temperature. 

The experiments of reactive distillation were carried out in a double-neck round-bottom flask working as a batch reactor. The reaction vessel was heated using a heating mantle and a magnetic stirrer was applied to create homogeneous slurry as reaction mixture. 

A mixture of 2-iodotoluene (8.78 g, 0.04 mol) and trimethyl phosphite (24.8 g, 0.20 mol) was placed in a 45-ml, double-jacketed silica reaction vessel. The mixture was degassed by flushing with dry nitrogen for 5 min and irradiated with a 450-watt Hanovia (Model 679A-10) high-pressure quartz mercury vapor lamp fitted with an aluminum reflector head. The lamp was placed 5 cm from the inner portion of the reaction vessel. The reaction temperature was maintained at 0°C by the circulation of coolant from a thermostatically controlled refrigeration unit. Irradiation was continued at this temperature for 24 h. At the end of this time, the volatile materials were removed with a water aspirator, and the residue was vacuum distilled (96 to 97°C/0.25 torr) to give the dimethyl 2-methylphenylphosphonate (7.28 g, 91%). 

XANES to ensure the quality of the synthates. Three batches of ferrihydrite were synthesized and precipitates were washed 5-6 times to ensure a chloride-free synthate. Ferrihydrite precipitates were redispersed in 200 mL of double deionized (DDI) water at (1) room temperature (25°C), as well as preheated in water baths to temperatures of (2) 50°C and (3) 75°C. For all of these slurries, pH was kept constant at 10 using 1M KOH. 40 mL samples were pipetted from each reaction vessel after 0, 1,2, 3, and 7 days. Slurries were centrifuged, washed three times with DDI water and air dried for analyses (BET, XRD, and XANES). BET analyses were used to evaluate the decrease in surface areas with increasing crystallinity, and XRD and XANES were used to detail the structural and speciation changes in iron. 

Le Chatelier s principle also predicts that the yield of ammonia is greater at higher pressures. High-pressure plants are expensive to huild and maintain, however. In fact, the first industrial plant that manufactured ammonia had its reaction vessel blow up. A German chemical engineer, Carl Bosch, solved this problem by designing a double-walled steel vessel that could operate at several hundred times atmospheric pressure. Modern plants operate at pressures in the range of 20 200 kPa to 30 400 kPa. 

Reaction vessels used in this procedure were flame dried under vacuum and all operations carried out in an oxygen-free, argon or nitrogen atmosphere. To a solution of 465.7 mg (2.3019 mmol) of 4,4-dimethyl-6-ethynyl-thiochroman in 4 ml of dry tetrahydrofuran at 0°C was added dropwise 1.5 ml of 1.6 M (2.4 mmol) n-butyl lithium in hexane. This was stirred at 0°C for 10 min and at room temperature for 10 min, cooled again to 0°C and then treated with a solution of 330 mg (2.4215 mmol) of fused ZnCI2 in 4 ml dry tetrahydrofuran using a double ended needle. Thereafter the... 

SOPHAS M (Figure 13.10) is an automatic modular solid-phase synthesizer based on a robotic system. Synthesis can be carried out in a variety of reaction vessels, such as 96-well microtiter plates, tubes, or vials. The vessels are mowed on the 1- or 1.2-m-length workbench in aluminum carriers (12 mm x 86 mm) by a robotic arm. The content of the reaction vessels is isolated from the atmosphere by a pierceable double seal. There are four independent pipetting probes on the synthesizer. Each probe has three independent channels. The channels allow the synthesizer to simultaneously aspirate and add washing solvents and nitrogen. 

---