Rate law equation

Empirical Models. In the case of an empirical equation, the model is a power law rate equation that expresses the rate as a product of a rate constant and the reactant concentrations raised to a power (17), such as... 

Related to the preceding is the classification with respect to oidei. In the power law rate equation / = /cC C, the exponent to which any particular reactant concentration is raised is called the order p or q with respect to that substance, and the sum of the exponents p + q is the order of the reaction. At times the order is identical with the molecularity, but there are many reactions with experimental orders of zero or fractions or negative numbers. Complex reactions may not conform to any power law. Thus, there are reactions of ... 

Over the usual hmited range of conditions, a power law rate equation often appears to be as satisfactory a fit of the data as a more complex Langmuir-Hinshelwood equation. The example of the hydrogenation of oc tenes is shown in Fig. l-2d and l-2e, and another case follows. 

Simpler, mostly power law rate equations for the production of mixed alcohols from synthesis gas are cited by Forzatti, Tronconi, and... 

Each group of molecules reacts independently of any other group, that is, as a batch reaclor. Batch conversion equations for power law rate equations are ... 

When uniform poisoning occurs the specific rate declines by a factor 1 — P where is the fractional poisoning. Then a power law rate equation becomes... 

For laminar flow, the velocity at the centerline is Uq = 2u. For a power law rate equation = kO, the differential material balance on a streamline is... 

Three of the more frequently occurring examples of power law rate equations are... 

The units of the specific rate depend on the order of a power law rate equation and on the units of the rate of reaction which are basically, (mass)/(time) (volume). 

Pyrolysis of ethyl benzene was carried out at 950 F in a flow reactor (Rase Kirk, Chem Eng Prog 30 35, 1954) with the tabulated results at two pressures. Find a power law rate equation for this process. 

What power law rate equation fits the data ... 

The flow distribution in a cylindrical vessel has the shape of an isosceles triangle with apex on the axis, thus u = u0(j 3j, /3 = r/R. Find the mean velocity and the mean conversion of a reaction with a power law rate equation. Compare with laminar and uniform flows. 

Over limited ranges of conditions, power law rate equations often are as adequate as those found by detailed chemical or L-H mechanisms. 

For simple power law rate equations the effectiveness can be expressed in terms of the Thiele modulus, Eq 7.28. In those cases restriction is to irreversible, isothermal reactions without volume change. Other cases can be solved, but then the Thiele modulus alone is not sufficient for a correlation. 

The balances are written in terms of volumetric flow rates, concentrations and a power law rate equation, rc = kCn. The sink term is rcVr the rate of reaction in a reference volume. Vr is the instantaneous volume occupied by the fluid in the vessel and Vrt is the capacity of the vessel. 

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