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  2. Rate equation - Wikipedia

    en.wikipedia.org/wiki/Rate_equation

    If the concentration of a reactant remains constant (because it is a catalyst, or because it is in great excess with respect to the other reactants), its concentration can be included in the rate constant, leading to a pseudo–first-order (or occasionally pseudo–second-order) rate equation. For a typical second-order reaction with rate ...

  3. Arrhenius equation - Wikipedia

    en.wikipedia.org/wiki/Arrhenius_equation

    In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates.The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that the van 't Hoff equation for the temperature dependence of equilibrium constants suggests such a formula for the rates of both forward and ...

  4. Order of accuracy - Wikipedia

    en.wikipedia.org/wiki/Order_of_accuracy

    Consider , the exact solution to a differential equation in an appropriate normed space (, | | | |). Consider a numerical approximation u h {\displaystyle u_{h}} , where h {\displaystyle h} is a parameter characterizing the approximation, such as the step size in a finite difference scheme or the diameter of the cells in a finite element method .

  5. Reaction rate constant - Wikipedia

    en.wikipedia.org/wiki/Reaction_rate_constant

    where A and B are reactants C is a product a, b, and c are stoichiometric coefficients,. the reaction rate is often found to have the form: = [] [] Here ⁠ ⁠ is the reaction rate constant that depends on temperature, and [A] and [B] are the molar concentrations of substances A and B in moles per unit volume of solution, assuming the reaction is taking place throughout the volume of the ...

  6. Euler method - Wikipedia

    en.wikipedia.org/wiki/Euler_method

    Consider the problem of calculating the shape of an unknown curve which starts at a given point and satisfies a given differential equation. Here, a differential equation can be thought of as a formula by which the slope of the tangent line to the curve can be computed at any point on the curve, once the position of that point has been calculated.

  7. Continuous stirred-tank reactor - Wikipedia

    en.wikipedia.org/wiki/Continuous_stirred-tank...

    Plugging in the first CSTR equation to the second: = (+) Therefore for m identical CSTRs in series: C A m = C A o ( 1 + k τ ) m {\displaystyle C_{Am}={\frac {C_{Ao}}{(1+k\tau )^{m}}}} When the volumes of the individual CSTRs in series vary, the order of the CSTRs does not change the overall conversion for a first order reaction as long as the ...

  8. Thiele modulus - Wikipedia

    en.wikipedia.org/wiki/Thiele_modulus

    Then the Thiele modulus for a first order reaction is: = From this relation it is evident that with large values of , the rate term dominates and the reaction is fast, while slow diffusion limits the overall rate. Smaller values of the Thiele modulus represent slow reactions with fast diffusion.

  9. Rate-determining step - Wikipedia

    en.wikipedia.org/wiki/Rate-determining_step

    In fact, however, the observed reaction rate is second-order in NO 2 and zero-order in CO, [5] with rate equation r = k[NO 2] 2. This suggests that the rate is determined by a step in which two NO 2 molecules react, with the CO molecule entering at another, faster, step. A possible mechanism in two elementary steps that explains the rate ...