Equilibrium shifts

The high tendency of the TaF6 complex to undergo solvation initiates partial hydrolysis of the TaF6 complex yielding HF. Any addition of HF to the solution leads to an increase in the F Ta ratio, which in turn shifts Equilibrium (49) to the left and results in the disappearance of the band at 880 cm 1. 

Chemical interaction with other metal ions shifts Equilibrium (52) to the right (alkaline side) and yields certain types of compounds according to the acidity of the added metal. 

A change in total pressure does not always shift equilibrium. The first reaction mentioned in this chapter exemplifies this ... 

Le Chatelier s Principle, the removal of Zn+2 tends to shift equilibrium toward the products. Therefore, removing Zn+2 increases the tendency for reaction (63) to occur. Our prediction of reaction is still valid. 

Actually, a similar approach was used in studying the oxidative addition of methane to an iridium complex. Hydrocarbon solvents would have reacted faster than methane with the photochemically produced unsaturated iridium species, therefore J.K. Hoyano et al chose perfluorinated hexane as being an inert solvent. The elevated pressure was necessary in order to increase the concentration of the methane in the solution sufficiently to shift equilibrium (15) to the right /20/. 

Following the lead in the study of anionic polymerisations, several workers used common-ion salts to shift equilibrium (11) in attempts to determine kp and by means of... 

An MCFC operating on 1000 Ib/hr of fuel gas and a 70% air/30% CO2 oxidant has a fuel and oxidant utilization of 75% and 50% respectively. With the fuel and oxidant composition and molecular weights listed below, (a) How much hydrogen will be consumed in lb mol/hr (b) How much oxygen is consumed in lb mol/hr (c) What are the required air and oxidant flow rates in lb mol/hr (d) How much CO2 is transferred from the cathode to the anode (e) What is the composition of the effluent (spent) fuel and oxidant streams in mol % (ignoring the water gas shift equilibrium) ... 

For the above example, determine the composition of the effluent (spent) fuel stream in mol % including the effect of the water gas shift equilibrium. Assume an effluent temperature of 1200°F. 

These concentrations are now in equilibrium. The following table summarizes the effect of accounting for the water gas shift equilibrium. 

For the 15% of the fuel that is not utilized in the cell reaction we shall simply employ the reforming reaction. To the resulting gas composition, we will then impose the water gas shift equilibrium. 

Itoh, N., Y. Shindo, K. Haraya and T. Hakuta. 1988. A membrane reactor using microporous glass for shifting equilibrium of cyclohexane dehydrogenation. J. Chem. Eng. Japan 21(4) 399-404. 

Pound force x seo/lb mass shifting equilibrium pressure ratio 1000 14.7. 

E) The sign of AH° is positive, therefore the reaction is endothermic (heat is a reactant). Lowering the temperature will shift the equilibrium in the direction that produces heat (to the left). Adding N2 will not shift equilibrium because N2 is neither a prodnct nor reactant. All other choices will cause the equilibrium to shift to the right. 

Propellant Performance Data. Specific impulse and chamber temperature for a number of more common hypergolic propellant combinations are in the following table. Hie values are based on shifting equilibrium conditions with a chamber pressure of 1000 psia. Data are from Ref 33... 

The differences in reactions at different reactor positions was studied by Springmann et al. who reported product compositions for ATR of model compounds as a function of reactor length in a metal monolith coated with a proprietary noble metal containing Rh. As expected, the oxidation reactions take place at the reactor inlet, followed by the SR, shift, and methanation reactions. Figure 32 shows the product concentration profiles for a 1-hexene feed, which are typical results for all the fuels tested. These results show that steam, formed from the oxidation reactions, reaches a maximum shortly after the reactor inlet, after which it is consumed in the shift and reforming reactions. H2, CO and CO2 concentrations increase with reactor length and temperature. In this reactor, shift equilibrium is not reached, and the increase in CO with distance from the inlet is the net result of the shift and SR reactions. Methane is... 

Figure 24. Composition diagram of chamber flame temperature, °F., for ammonium perchlorate-aluminum-polybutadiene/BITA propellant. Pc = 1000 p.s.i.a. shifting equilibrium...

This table illustrates the performances that may be achieved through combination of various oxidizer and fuel types. The numbers in the table represent theoretical calculations of I8 (seconds) at standard conditions of 1000 p.s.i.a. and shifting equilibrium with optimum expansion to sea level conditions (using the "typical procedure previously described). The thermodynamic properties of the propellants and the potential reac-... 

Specific Impulse at 100 p.s.i.a. Chamber Pressure, Shifting Equilibrium, Optimum Expansion to Sea Level... 

Values calculated by Aerojet-General Corp. assuming shifting equilibrium and optimum expansion from 1000 to 14.7 p.s.i.a. 

The above are equilibrium reactions, and their successful exploitation requires that they be carried out under conditions in which the equilibrium favors the product. Specifically, this requires that the adsorbed species in Reactions (D)-(I) not be held so tightly on the catalyst surfaces as to inhibit the reaction. On the other hand, strong interaction between adsorbate and catalyst is important to break the bonds in the reactant species. Optimization involves finding a compromise between scission and residence time on the surface. Although we are especially interested in metal surfaces, those constituents known as promoters in catalyst mixtures are also important. It is known, for example, that the potassium in the catalyst used for the ammonia synthesis shifts Equilibrium (F) to the right and also increases the rate of Reaction (D) by lowering its activation energy from 12.5 kJ mole to about zero. 

Pour 2-3 ml of chlorine water into a test tube and add a sodium hydroxide solution dropwise. How can the vanishing of the colour and odour of the chlorine water be explained How does the alkali shift equilibrium in the reaction between chlorine and water State le Chatelier s principle. 

See Section 16-4E. Reducing agent is usually aluminum isopropoxide 2-propanone is formed and is removed by distillation, which shifts equilibrium to right. Carbon-carbon double bonds are unaffected. 

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