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  2. Standard solution - Wikipedia

    en.wikipedia.org/wiki/Standard_solution

    An example of a secondary standard is sodium hydroxide, a hydroscopic compound that is highly reactive with its surroundings. The concentration of a standard solution made with sodium hydroxide may fluctuate overtime due to the instability of the compound, requiring for calibration using a primary standard before use.

  3. Primary standard - Wikipedia

    en.wikipedia.org/wiki/Primary_standard

    A primary standard in metrology is a standard that is sufficiently accurate such that it is not calibrated by or subordinate to other standards. Primary standards are defined via other quantities like length, mass and time. Primary standards are used to calibrate other standards referred to as working standards. [1] [2] See Hierarchy of Standards.

  4. Titration - Wikipedia

    en.wikipedia.org/wiki/Titration

    Science Aid: A simple explanation of titrations including calculation examples; Titration freeware - simulation of any pH vs. volume curve, distribution diagrams and real data analysis; Graphical method to solve acid-base problems, including titrations; Graphic and numerical solver for general acid-base problems - Software Program for phone and ...

  5. Analytical chemistry - Wikipedia

    en.wikipedia.org/wiki/Analytical_chemistry

    Examples of rapidly expanding fields in this area are genomics, DNA sequencing and related research in genetic fingerprinting and DNA microarray; proteomics, the analysis of protein concentrations and modifications, especially in response to various stressors, at various developmental stages, or in various parts of the body, metabolomics, which ...

  6. List of international common standards - Wikipedia

    en.wikipedia.org/wiki/List_of_international...

    These standards are conventionally accepted as best practice and used globally by industry and organizations. In circumstances and situations there are certain methods and systems that are used as benchmarks, guidelines or protocols for communication , measurement , orientation , reference for information , science , symbols and time .

  7. Standard (metrology) - Wikipedia

    en.wikipedia.org/wiki/Standard_(metrology)

    An example of a primary standard was the international prototype of the kilogram (IPK) which was the master kilogram and the primary mass standard for the International System of Units (SI). The IPK is a one kilogram mass of a platinum-iridium alloy maintained by the International Bureau of Weights and Measures (BIPM) in Sèvres, France.

  8. Acid–base titration - Wikipedia

    en.wikipedia.org/wiki/Acid–base_titration

    For example: HCl + NaOH → NaCl + H 2 O. Acidimetry is the specialized analytical use of acid-base titration to determine the concentration of a basic (alkaline) substance using standard acid. This can be used for weak bases and strong bases. [8] An example of an acidimetric titration involving a strong base is as follows: Ba(OH) 2 + 2 H + → ...

  9. National Ambient Air Quality Standards - Wikipedia

    en.wikipedia.org/wiki/National_Ambient_Air...

    Primary and Secondary 0.12 ppm (235 μg/m 3) 1-hour a: expected number of days per calendar year, with maximum hourly average concentration greater than 0.12 ppm, is equal to or less than 1 40 CFR 50.9: Primary and Secondary 0.070 ppm (140 μg/m 3) 8-hour Annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years 40 CFR 50.19