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  2. Gravimetric analysis - Wikipedia

    en.wikipedia.org/wiki/Gravimetric_analysis

    Gravimetric analysis describes a set of methods used in analytical chemistry for the quantitative determination of an analyte (the ion being analyzed) based on its mass. The principle of this type of analysis is that once an ion's mass has been determined as a unique compound, that known measurement can then be used to determine the same analyte's mass in a mixture, as long as the relative ...

  3. Sulfate nitrates - Wikipedia

    en.wikipedia.org/wiki/Sulfate_nitrates

    Two sulfate nitrates are in the class of anthropogenic compounds, accidentally made as a result of human activities in fertilizers that are a mix of ammonium nitrate and ammonium sulfate, and also in the atmosphere as polluting ammonia, nitrogen dioxide, and sulfur dioxide react with the oxygen and water there to form solid particles.

  4. Nitrogen dioxide - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_dioxide

    One of several nitrogen oxides, nitrogen dioxide is a reddish-brown gas. It is a paramagnetic , bent molecule with C 2v point group symmetry . Industrially, NO 2 is an intermediate in the synthesis of nitric acid , millions of tons of which are produced each year, primarily for the production of fertilizers .

  5. Nitrate test - Wikipedia

    en.wikipedia.org/wiki/Nitrate_test

    A common nitrate test, known as the brown ring test [2] can be performed by adding iron(II) sulfate to a solution of a nitrate, then slowly adding concentrated sulfuric acid such that the acid forms a layer below the aqueous solution. A brown ring will form at the junction of the two layers, indicating the presence of the nitrate ion. [3]

  6. Sulfate - Wikipedia

    en.wikipedia.org/wiki/Sulfate

    This is a common laboratory test to determine if sulfate anions are present. The sulfate ion can act as a ligand attaching either by one oxygen (monodentate) or by two oxygens as either a chelate or a bridge. [7] An example is the complex Co 2 (SO 4)] + Br − [7] or the neutral metal complex PtSO 4 (PPh 3) 2] where the sulfate ion is acting as ...

  7. Kjeldahl method - Wikipedia

    en.wikipedia.org/wiki/Kjeldahl_method

    Kjeldahl method is not applicable to compounds containing nitrogen in nitro and azo groups and nitrogen present in rings (e.g. pyridine, quinoline, isoquinoline) as nitrogen of these compounds does not convert to ammonium sulfate under the conditions of this method.

  8. Reference materials for stable isotope analysis - Wikipedia

    en.wikipedia.org/wiki/Reference_materials_for...

    The δ values and absolute isotope ratios of common reference materials are summarized in Table 1 and described in more detail below. Alternative values for the absolute isotopic ratios of reference materials, differing only modestly from those in Table 1, are presented in Table 2.5 of Sharp (2007) [1] (a text freely available online), as well as Table 1 of the 1993 IAEA report on isotopic ...

  9. Sulfur assimilation - Wikipedia

    en.wikipedia.org/wiki/Sulfur_assimilation

    Sulfite may also be oxidized to sulfate, extra- and intracellularly by peroxidases or non-enzymatically catalyzed by metal ions or superoxide radicals and subsequently reduced and assimilated again. Excessive sulfate is transferred into the vacuole; enhanced foliar sulfate levels are characteristic for exposed plants.