Gases percentage decomposition

Fig. 10. Percentage decomposition of N2O on a nickel oxide catalyst, with various additions of Li2O and InjOs, as a function of the temperature, according to Hauffe, Glang, and EngeU. (Composition of the reacting gas 15% N2O and 86% air flow rate 1200 cm. /hour.)...

The time in which a given molecule remained in the tube was estimated by dividing the volume of the tube by the rate of gas flow as determined with a flowmeter. The ratio of nitrites to total acidity gave the ratio N()2/(N2O5+NO2) and hence a measure of the percentage decomposition. The specific decomposition rate k was then calculated for various temperatures and for different pressures. Within the limit of experimental accuracy the specific decomposition rate of nitrogen pentoxide was the same as that determined by the static method, already described, and furthermore, this same constant was maintained down to a few millimeters and even to tenths of millimeters. 

Fig. 4. Thermal decomposition of HAN (80 wt.-%)-water mixture at 200 °C. Gas percentage versus time after the HAN injection (100 xL).

The relative abundance of neutral SiH and H2 species have been measured as a function of power, pressure, flow rate, and dilution. For low power levels, eg, 5 W, up to 50% of the SiH gas is dissociated and the percentage increases to 80% for a power of 50 W. The decomposition of SiH gas proceeds more readily with lower flow rates. These observations, coupled with infrared (ir) measurements performed on the films, suggest that deposition under conditions in which the silane gas is not entirely decomposed leads to a majority of SiH units, whereas those deposited under conditions in which silane is strongly dissociated contain a majority of dihydride units leading to a deterioration of the semiconductor. Also, when the dwell time of SiH in the plasma region increases, the resultant film exhibits a pronounced peak at 2090 cm from the ir spectra corresponding to S1H2 inclusion. 

In considering the chemical reactions based on the light olefins it is obvious that natural gas liquids are at a disadvantage in comparison with the corresponding refinery cuts. These contain varying but substantial percentages of olefins as such—the results of thermal and catalytic decomposition of the heavier petroleum molecules. But refinery olefins are also in demand for synthesis to premium motor fuels. It is fortunate that there are abundant supplies of natural gas paraffins for conversion to provide adequate raw material for our olefin chemistry. 

The estimation of individual components and different synthetics was effectively achieved by gas chromatography after simple silylation (10). Figure 2 shows the separation obtained, clearly away from other volatiles in a capsicum extract. The individual capsaicinoids were quantitated in relation to vanillyl octanamide as the internal standard chosen, because it eluted just prior to the capsaicinoids and the response factors of the capsaicinoids with reference to this standard were close to unity. The standardised conditions were as follows Silylation with N,0-bis (trimethylsilyl)-trifluoroacetamide in tetrahydrofuran gave clear rapid reaction at room temperature. The silylated extracts were injected directly on to a stainless steel column of 2 m x 3 mm, filled with 3% SE-30 on Chromosorb-GHP, (100-120 mesh) the column temperature was programmed from 170° to 215°C at 4°/min. and held at 215°C for 10 minutes. The injection port temperature was important for rapid volatilisation of all the components without decomposition, and was fixed at 200°C. The flame ionisation detector temperature was kept at 250°C, and nitrogen flow at 20 ml/min. The percentages of the individual capsaicinoids were calculated from the areas of the peaks, the response factors, and the weight and area of the reference compound. 

Photochemical, thermal, and transition metal catalyzed decomposition of diazoacetonitrile in the presence of an alkene yields cyclopropanecarbonitriles by transfer of cyanocarbene (see Houben-Weyl, Vol. E19b, pl202). If the UV irradiation was carried out in (Z)-but-2-ene as solvent, cw-2,3-dimethylcyclopropane-l-carbonitrile (c -l) was formed as the major product cisjtrans 94 6). The percentage of the franj-product can be decreased by the addition of a radical scavenger, such as 1,2-diphenylethene, whereas it can be increased by dilution with dichloromethane. By carrying out the decomposition of diazoacetonitrile as a gas-phase thermolysis, fm i -2,3-dimethylcyclopropane-l-carbonitrile (irans-l) becomes the major product of the cyclopropanation cisltrans 38 62). ... 

Ethylene is frequently formed when non-volatile organic compounds are subjected to destructive distillation, or when hydrocarbons are heated to such a temperature that they undergo decomposition. The ethylene found in coal gas and in carbureted water gas is produced in this way. Natural gas also contains a small percentage of this hydrocarbon. The luminosity of illuminating gas is due in part to the presence of ethylene, which is present in the gas to the extent of from four to five per cent. 

The weight lost by a sample heated to a given temperature helps the inorganic or analytical chemist to determine the composition of a compound and follow the reactions involved in its decomposition. It also enables the analytical chemist to identify crystals of unknown composition or determine the percentage of a given compound in a mixmre of compounds. For example, if pure calcium carbonate (CaCOs) is heated to 850°C, it loses 44% of its weight (Fig. 16.1). Also, the gas evolved can be collected and identified as CO2. This observation virtually confirms that the reaction... 

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