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  2. Electroanalytical methods - Wikipedia

    en.wikipedia.org/wiki/Electroanalytical_methods

    Coulometry uses applied current or potential to convert an analyte from one oxidation state to another completely. In these experiments, the total current passed is measured directly or indirectly to determine the number of electrons passed. Knowing the number of electrons passed can indicate the concentration of the analyte or when the ...

  3. Stoichiometry - Wikipedia

    en.wikipedia.org/wiki/Stoichiometry

    This is illustrated in the image here, where the balanced equation is: CH 4 + 2 O 2 → CO 2 + 2 H 2 O. Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. This particular chemical equation is an example of complete combustion. Stoichiometry measures these ...

  4. X-ray crystallography - Wikipedia

    en.wikipedia.org/wiki/X-ray_crystallography

    The distance between two bonded atoms is a sensitive measure of the bond strength and its bond order; thus, X-ray crystallographic studies have led to the discovery of even more exotic types of bonding in inorganic chemistry, such as metal-metal double bonds, [63] [64] [65] metal-metal quadruple bonds, [66] [67] [68] and three-center, two ...

  5. Amount of substance - Wikipedia

    en.wikipedia.org/wiki/Amount_of_substance

    Historically, the mole was defined as the amount of substance in 12 grams of the carbon-12 isotope.As a consequence, the mass of one mole of a chemical compound, in grams, is numerically equal (for all practical purposes) to the mass of one molecule or formula unit of the compound, in daltons, and the molar mass of an isotope in grams per mole is approximately equal to the mass number ...

  6. Conservation of mass - Wikipedia

    en.wikipedia.org/wiki/Conservation_of_mass

    Many other convection–diffusion equations describe the conservation and flow of mass and matter in a given system. In chemistry, the calculation of the amount of reactant and products in a chemical reaction, or stoichiometry, is founded on the principle of conservation of mass. The principle implies that during a chemical reaction the total ...

  7. Chemical equation - Wikipedia

    en.wikipedia.org/wiki/Chemical_equation

    A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas.The reactant entities are given on the left-hand side and the product entities are on the right-hand side with a plus sign between the entities in both the reactants and the products, and an arrow that points towards the products to show the direction of the reaction. [1]

  8. Length measurement - Wikipedia

    en.wikipedia.org/wiki/Length_measurement

    The basic idea behind a transit-time measurement of length is to send a signal from one end of the length to be measured to the other, and back again. The time for the round trip is the transit time Δt, and the length ℓ is then 2ℓ = Δt*"v", with v the speed of propagation of the signal, assuming that is the same in both directions.

  9. Rydberg formula - Wikipedia

    en.wikipedia.org/wiki/Rydberg_formula

    In 1890, Rydberg proposed on a formula describing the relation between the wavelengths in spectral lines of alkali metals. [2]: v1:376 He noticed that lines came in series and he found that he could simplify his calculations using the wavenumber (the number of waves occupying the unit length, equal to 1/λ, the inverse of the wavelength) as his unit of measurement.