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  2. Van 't Hoff factor - Wikipedia

    en.wikipedia.org/wiki/Van_'t_Hoff_factor

    For most non-electrolytes dissolved in water, the van 't Hoff factor is essentially 1. For most ionic compounds dissolved in water, the van 't Hoff factor is equal to the number of discrete ions in a formula unit of the substance. This is true for ideal solutions only, as occasionally ion pairing occurs in solution. At a given instant a small ...

  3. Residence time - Wikipedia

    en.wikipedia.org/wiki/Residence_time

    The residence time of a fluid parcel is the total time that the parcel has spent inside a control volume (e.g.: a chemical reactor, a lake, a human body).The residence time of a set of parcels is quantified in terms of the frequency distribution of the residence time in the set, which is known as residence time distribution (RTD), or in terms of its average, known as mean residence time.

  4. Chilton and Colburn J-factor analogy - Wikipedia

    en.wikipedia.org/wiki/Chilton_and_Colburn_J...

    This equation permits the prediction of an unknown transfer coefficient when one of the other coefficients is known. The analogy is valid for fully developed turbulent flow in conduits with Re > 10000, 0.7 < Pr < 160, and tubes where L/d > 60 (the same constraints as the Sieder–Tate correlation). The wider range of data can be correlated by ...

  5. Van 't Hoff equation - Wikipedia

    en.wikipedia.org/wiki/Van_'t_Hoff_equation

    The Van 't Hoff equation relates the change in the equilibrium constant, K eq, of a chemical reaction to the change in temperature, T, given the standard enthalpy change, Δ r H ⊖, for the process. The subscript r {\displaystyle r} means "reaction" and the superscript ⊖ {\displaystyle \ominus } means "standard".

  6. Darcy's law - Wikipedia

    en.wikipedia.org/wiki/Darcy's_law

    Darcy's law is an equation that describes the flow of a fluid through a porous medium and through a Hele-Shaw cell.The law was formulated by Henry Darcy based on results of experiments [1] on the flow of water through beds of sand, forming the basis of hydrogeology, a branch of earth sciences.

  7. Chemical oxygen demand - Wikipedia

    en.wikipedia.org/wiki/Chemical_oxygen_demand

    In environmental chemistry, the chemical oxygen demand (COD) is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution, which in SI units is milligrams per liter ( mg / L ).

  8. Green chemistry metrics - Wikipedia

    en.wikipedia.org/wiki/Green_chemistry_metrics

    The first general metric for green chemistry remains one of the most flexible and popular ones. Roger A. Sheldon’s environmental factor (E-factor) can be made as complex and thorough or as simple as desired and useful. [10] The E-factor of a process is the ratio of the mass of waste per mass of product:

  9. Equivalent concentration - Wikipedia

    en.wikipedia.org/wiki/Equivalent_concentration

    There are three common types of chemical reaction where normality is used as a measure of reactive species in solution: In acid-base chemistry, normality is used to express the concentration of hydronium ions (H 3 O +) or hydroxide ions (OH −) in a solution. Here, ⁠ 1 / f eq ⁠ is an integer value. Each solute can produce one or more ...