Xenon tetrafluoride reactions

FIGURE 15.27 Crystals of xenon tetrafluoride, XeF4. This compound was first prepared in 1062 by the reaction of xenon and fluorine at 6 atm and 4(J(J C. 

The xenon fluorides are used to prepare the xenon oxides and oxoacids and, in a series of disproportionations, to bring the oxidation number of xenon up to +8. First, xenon tetrafluoride is hydrolyzed to xenon trioxide, Xe03 in a disproportionation reaction ... 

Xenon tetrafluoride is a powerful oxidizing agent. In an acidic solution, it is reduced to xenon. Write the corresponding half-reaction. 

Xenon difluoride (or the tetrafluoride, or their mixtures) could not be caused to detonate by impact. Xenon difluoride and xenon tetrafluoride both may cause explosion in contact with acetone, aluminium, pentacarbonyliron, styrene, polyethylene, lubricants, paper, sawdust, wool or other combustible materials. Their vigorous reactions with ethanol, potassium iodate or potassium permanganate are not explosive, however. 

Interaction of the yellow hexafluoride with silica to give xenon tetrafluoride oxide must be interrupted before completion (disappearance of colour) to avoid the possibility of formation and detonation of xenon trioxide [1]. An attempt to collect the hexafluoride in fused silica traps at — 20°C after separation by preparative gas chromatography failed because of reaction with the silica and subsequent explosion of the oxygen compounds of xenon so produced [2],... 

In the reaction of the pentaoxide with xenon tetrafluoride oxide to give xenon difluoride dioxide and nitryl fluoride, the xenon tetrafluoride oxide must be used in excess to avoid formation of xenon trioxide, which forms a sensitive explosive mixture with xenon difluoride dioxide. 

Xenon tetrafluoride undergoes reactions that are similar to those of the interhalogens. For example, the XeF3+ cation is generated when XeF4 reacts with a very strong Lewis acid, such as BiF5. 

O O In the early 1960s, Neil Bartlett, at the University of British Columbia, was the first person to synthesize compounds of the noble gas xenon. A number of noble gas compounds (such as XeF2, XeF4, XeFe, and XeOs) have since been synthesized. Consider the reaction of xenon difluoride with fluorine gas to produce xenon tetrafluoride. 

Xenon also forms many fluoroanions and their salts, mostly prepared from xenon tetrafluoride and hexafluoride. Such compounds include Na+XeFs and Cs" XeF7- formed by reactions of xenon fluorides with sodium fluoride or cesium fluoride. The dicesium xenon octafluoride, Cs2XeFs, is a stable yellow solid that decomposes above 400°C. 

The relatively recently discovered compounds of the erstwhile inert gases have already been studied in systems with oxides of nitrogen. Johnston and Woolfolk232 reported the reaction rates of xenon difluoride and xenon tetrafluoride with nitric oxide in the temperature range 300-350°K and at pressures between 0.1 and 30 torr. The reactions were followed by a mass spectrometer, separated from the reaction cell by a pinhole. There were serious problems, both in carrying out the experiment and in analyzing the data, but the results seem reliable. In... 

The reaction of hexafluoropropene with xenon tetrafluoride gives octafluoropropane (3) in 94 % yield after 15 hours however, the reaction of xenon difluoride with hexafluoropropene... 

Both of these rules follow in a straightforward way from the properties of enthalpy changes. The first rule can be explained by recalling that the sip7i of AH indicates the direction of the heat flow at constant pressure. If the direction of the reaction is reversed, the direction of the heat flow is also reversed. To see this, consider the preparation of xenon tetrafluoride, which was the first reported binary compound made from a noble gas ... 

Less than a year after Bartlett s report, a group at Argonne National Laboratory near Chicago prepared xenon tetrafluoride by reacting xenon and fluorine gases in a nickel reaction vessel at 400°C and 6 atm ... 

Xenon tetrafluoride with platinum tetrafluoride in iodine pentafluoride solution. —Although xenon tetrafluoride dissolved in iodine pentafluoride without reaction, no adduct could be isolated. Furthermore, this solution failed to react with platinum tetrafluoride even on prolonged reflux at 100°. 

Xenon tetrafluoride has been prepared by a number of methods. Irradiation of a mixture of xenon and fluorine with ultraviolet light produces xenon difluoride if the reaction product is immediately condensed from the gas phase. However, if the di fluoride is allowed to remain in the reaction zone, the tetrafluoride is produced. Passage of an electric discharge through a mixture of xenon and fluorine also produces xenon tetrafluoride. Perhaps the best method is the one in which xenon and fluorine are heated together either in a closed system or in a flow system. The method which uses a closed system allows a somewhat better control of purity and is described below. 

The apparatus used for the preparation and purification of xenon tetrafluoride is shown in Fig. 10. The total volume of the manifold including the U-tubes, but excluding all reaction and storage vessels, is about 105 ml. All parts are fabricated of nickel or Monel and are pretreated by... 

Xenon hexafluoride may be prepared in essentially the same way as xenon tetrafluoride (synthesis 66), except for increasing the fluorine-to-xenon ratio and the final pressure at reaction temperature.Variations of temperature, pressure, mol ratio, and time make possible the formation of xenon difluoride, xenon tetrafluoride, or xenon hexafluoride. The conditions described below have been found to give good yields and purity for xenon hexafluoride. 

Since Bartlett s discovery, many other noble gas compounds have been made. All involve very electronegative elements. Most are compounds of Xe, and the best characterized compounds are xenon fluorides. Oxygen compounds are also well known. Reaction of Xe with F2, an extremely strong oxidizing agent, in different stoichiometric ratios produces xenon difluoride, Xep2 xenon tetrafluoride, XeF and xenon hexafluoride, XeFg, all colorless crystals (Table 24-3). 

How many grams of xenon oxide tetrafluoride, XeOF4, and how many liters of HF at STP could be prepared, assuming complete reaction of 10.5 g of xenon tetrafluoride, XeF4, with a stoichiometric quantity of water according to the equation below ... 

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