Dissociation also temperature

The solid is pale blue the liquid is an intense blue at low temperatures but the colour fades and becomes greenish due to the presence of NO2 at higher temperatures. The dissociation also limits the precision with which physical properties of the compound can be determined. At 25°C the dissociative equilibrium in the gas phase is characterized by the following thermodynamic quantities ... 

Support for the special reactivity of hot oxygen adatoms also came from Matsushima s temperature-programmed desorption study4 of CO oxidation at Pt(lll), when CO and 02 were coadsorbed at low temperature with C02 desorbed at 150 K, the temperature at which 02 dissociates. This temperature is some 150 K lower than that for C02 formation when oxygen is preadsorbed (thermally accommodated) at the Pt(lll) surface. 

The oxidation behavior of platinum metals is of importance for their applications at high temperatures. These metals form solid oxides and also volatilize as oxides at higher temperature in an oxidizing atmosphere. Most of the gaseous oxides are stable only at high temperatures and usually contain the metal in its highest oxidation states. Palladium is an exception since it dissolves oxygen in the solid state and only forms the solid oxide PdO which dissociates at temperatures above 800 °C. 

The dissociation also is rapid helow this temperature (between 450°C to 850°C), however, only in the presence of a catalyst, such as sdica, platinum sulfide or cohalt molybdate. Other sulfur species are also produced in the reaction. 

Once the temperature is raised to T/K, then a % of the X2 (g) molecules are converted into X(g) molecules and there are two X molecules producedfor every X2 molecule dissociated also. Thus (xa/100) = 0.0 lxa molecules of X2 are converted to produce 2(xo /100) = 0.02xo ,Xmolecules. The concentration ofX2 therefore falls from the original concentration [X2, g] = x mol dm-3... 

In the opinion of Parmenter and Noyes, decomposition at 3130 A consists of a rapid process from an upper repulsive state of the aldehyde molecule and of a slower one from the vibrationally excited singlet state. A temperature-dependent triplet dissociation also occurs. However, quantitative results for this latter process could not be obtained in their investigations. 

Carbon monoxide is dissociatively adsorbed on the surfaces of those metals, such as iron or cobalt, which are active in hydrocarbon synthesis. On nickel, dissociation also occurs, although at higher temperatures than on iron. Chain... 

Other properties of association colloids that have been studied include calorimetric measurements of the heat of micelle formation (about 6 kcal/mol for a nonionic species, see Ref. 188) and the effect of high pressure (which decreases the aggregation number [189], but may raise the CMC [190]). Fast relaxation methods (rapid flow mixing, pressure-jump, temperature-jump) tend to reveal two relaxation times t and f2, the interpretation of which has been subject to much disagreement—see Ref. 191. A fast process of fi - 1 msec may represent the rate of addition to or dissociation from a micelle of individual monomer units, and a slow process of ti < 100 msec may represent the rate of total dissociation of a micelle (192 see also Refs. 193-195). 

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