Reaction vessels fluorine compounds

A number of detailed kinetic studies on the thermal reactions of fluorine compounds has been made in recent years by Atkinson and associates " at the Imperial College of Science and Technology, London. The static method has been largely used, with nickel, stainless steel, and occasionally, pyrex glass reaction vessels suitably aged after several decompositions of the fluorine compound. Glass vessels are attacked by fluorine compounds at high temperatures presumably with the formation of carbon monoxide and silicon fluoride -... 

A major decision that must be made is whether to carry out the experiment in an open or, better, a flow system, or alternatively in a closed or pressure system. Both reactions are equally well suited to be carried out in a flow system, as solid and non-volatile starting compounds react with the fluorine gas to form the desired non-volatile product together with volatile by-products. The latter are swept away by excess fluorine. In case of a closed system example (Eqn. (11)) turns out less favorable, as C1F will react with F2 to form C1F3, which in turn may also compete for the potassium component to form KC1F4. Under these conditions therefore a pure product is not expected. No such complications are to be expected with the second reaction (Eqn. (12)), which results in a very clean product. This very simple example is intended to demonstrate that, although for many experiments a flow system or a closed reaction vessel are mutually exchangeable, characteristic... 

Heat treatment of the S-type fluoride in a fluorine atmosphere Based on the results above mentioned, Fujimoto et al. developed a new fluorination procedure in order to prepare the perfluorinated pitch, and obtained two types of other fluorinated pitches [23,24], The new process is by the heat treatment at 200-400°C of S-type of fluorinated pitch prepared at relatively low temperature in a fluorine atmosphere. They firstly fluorinated the mesophase pitch at 70°C for 10 h (first step for the preparation of S-type fluorinated pitch) and then heated up to a selected temperature between 200°C and 400°C, and maintained this temperature for 12 h (second step for the heat-treatment of fluorinated pitch). Thus, they obtained two kinds of fluorocarbons, a transparent resin (R-type) and a liquid (L-type). L-type is a viscous fluid containing some volatile materials and the viscosity gradually becomes higher when it is kept for a few weeks in an air atmosphere even at ambient temperature. They reported that the R-type was obtained in the nickel boat in the heating zone and L-type at the bottom of the vertical reaction vessel which was cooled down by the water. Therefore, it is likely that the liquid fluorocarbon is formed by the vaporization of some component contained in the S-type fluoride or decomposition reaction during the heat treatment of the S-type fluoride. The yields of these compounds depends on the heat treatment temperature. In Fig. 3, the yields of the R-type and L-type fluorocarbons are plotted as a function of the heat treatment temperature of the S-type fluoride. The yield of the former decreases with increase of the heat treatment temperature and finally, at 400 C, it can not be obtained at all. On the other hand, the yield of the latter increases with increase of temperature and it is selectively obtained at 400°C. 

Xenon and fluorine will react to form binary compounds when a mixture of these two gases is heated to 400°C in a nickel reaction vessel. A 100.0-mL nickel container is filled with xenon and fluorine giving partial pressures of 1.24 atm and 10.10 atm, respectively, at a temperature of 25°C. The reaction vessel is heated to 400°C to cause a reaction to occur and then cooled to a temperature at which F2 is a gas and the xenon fluoride is a nonvolatile solid. The remaining F2 gas is transferred to another 100.0-mL nickel container where the pressure of F2 at 25°C is 7.62 atm. Assuming all of the xenon has reacted, what is the formula of the product ... 

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