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  2. Rate-determining step - Wikipedia

    en.wikipedia.org/wiki/Rate-determining_step

    As an example, consider the gas-phase reaction NO 2 + CO → NO + CO 2.If this reaction occurred in a single step, its reaction rate (r) would be proportional to the rate of collisions between NO 2 and CO molecules: r = k[NO 2][CO], where k is the reaction rate constant, and square brackets indicate a molar concentration.

  3. X-ray crystallography - Wikipedia

    en.wikipedia.org/wiki/X-ray_crystallography

    An X-ray diffraction pattern of a crystallized enzyme. The pattern of spots (reflections) and the relative strength of each spot (intensities) can be used to determine the structure of the enzyme. The relative intensities of the reflections provides information to determine the arrangement of molecules within the crystal in atomic detail.

  4. Reaction rate - Wikipedia

    en.wikipedia.org/wiki/Reaction_rate

    Iron rusting has a low reaction rate. This process is slow. Wood combustion has a high reaction rate. This process is fast. The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time. [1]

  5. High-energy X-rays - Wikipedia

    en.wikipedia.org/wiki/High-energy_X-rays

    High-energy X-rays or HEX-rays are very hard X-rays, with typical energies of 80–1000 keV (1 MeV), about one order of magnitude higher than conventional X-rays used for X-ray crystallography (and well into gamma-ray energies over 120 keV).

  6. X-ray fluorescence - Wikipedia

    en.wikipedia.org/wiki/X-ray_fluorescence

    X-ray diffraction (XRD) is still the most used method for structural analysis of chemical compounds. Yet, with increasing detail on the relation of K β {\displaystyle K_{\beta }} -line spectra and the surrounding chemical environment of the ionized metal atom, measurements of the so-called valence-to-core (V2C) energy region become ...

  7. Taft equation - Wikipedia

    en.wikipedia.org/wiki/Taft_equation

    where k s is the rate of the studied reaction and is the rate of the reference reaction (R = methyl). δ is a reaction constant that describes the susceptibility of a reaction series to steric effects. For the definition reaction series δ was set to 1 and E s for the reference reaction was set to zero. This equation is combined with the ...

  8. Sabatier principle - Wikipedia

    en.wikipedia.org/wiki/Sabatier_principle

    At high values of Δ f H, desorption becomes the rate-limiting step. The maximum rate, which is observed for the platinum group metals in this case, requires intermediate values of Δ f H, with the rate being a combination of the rate of adsorption and the rate of desorption. [3] Catalysts can exceed the Sabatier limit via catalytic resonance.

  9. Reaction progress kinetic analysis - Wikipedia

    en.wikipedia.org/wiki/Reaction_progress_kinetic...

    c) The rate of reaction progress (product formation) is monitored over time by methods such as reaction progress calorimetry or may be obtained by taking the first derivative of (a). d) Describing the rate of reaction progress with respect to consumption of starting material spreads the data into a more informative distribution than observed in ...