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  2. Hydrofluoric acid - Wikipedia

    en.wikipedia.org/wiki/Hydrofluoric_acid

    Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water.Solutions of HF are colorless, acidic and highly corrosive.A common concentration is 49% (48-52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling point near room temperature.

  3. Water splitting - Wikipedia

    en.wikipedia.org/wiki/Water_splitting

    Water splitting is the chemical reaction in which water is broken down into oxygen and hydrogen: [1] 2 H 2 O → 2 H 2 + O 2 Efficient and economical water splitting would be a technological breakthrough that could underpin a hydrogen economy .

  4. Heterogeneous water oxidation - Wikipedia

    en.wikipedia.org/wiki/Heterogeneous_Water_Oxidation

    Water splitting can be done at higher pH values as well however the standard potentials will vary according to the Nernst equation and therefore shift by -59 mV for each pH unit increase. However, the total cell potential (difference between oxidation and reduction half cell potentials) will remain 1.23 V.

  5. Stefan problem - Wikipedia

    en.wikipedia.org/wiki/Stefan_problem

    At the interface between the phases (in the classical problem) the temperature is set to the phase change temperature. To close the mathematical system a further equation, the Stefan condition, is required. This is an energy balance which defines the position of the moving interface.

  6. Thermochemical equation - Wikipedia

    en.wikipedia.org/wiki/Thermochemical_equation

    In thermochemistry, a thermochemical equation is a balanced chemical equation that represents the energy changes from a system to its surroundings. One such equation involves the enthalpy change, which is denoted with Δ H {\displaystyle \Delta H} In variable form, a thermochemical equation would appear similar to the following:

  7. Hypofluorous acid - Wikipedia

    en.wikipedia.org/wiki/Hypofluorous_acid

    2 HOF → 2 HF + O 2. This reaction is catalyzed by water. [2] It was isolated in the pure form by passing F 2 gas over ice at −40 °C, rapidly collecting the HOF gas away from the ice, and condensing it: [2] F 2 + H 2 O → HOF + HF. The compound has been characterized in the solid phase by X-ray crystallography [1] as a bent molecule with

  8. Darcy's law for multiphase flow - Wikipedia

    en.wikipedia.org/wiki/Darcy's_law_for_multiphase...

    The above equation is a vector form of the most general equation for fluid flow in porous media, and it gives the reader a good overview of the terms and quantities involved. Before you go ahead and transform the differential equation into difference equations, to be used by the computers, you must write the flow equation in component form.

  9. Proton-transfer-reaction mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Proton-transfer-reaction...

    Proton-transfer-reaction mass spectrometry (PTR-MS) is an analytical chemistry technique that uses gas phase hydronium reagent ions which are produced in an ion source. [1] PTR-MS is used for online monitoring of volatile organic compounds (VOCs) in ambient air and was developed in 1995 by scientists at the Institut für Ionenphysik at the ...