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  2. Winkler titration - Wikipedia

    en.wikipedia.org/wiki/Winkler_titration

    Dissolved oxygen (D.O.) is widely used in water quality studies and routine operation of water reclamation facilities to analyze its level of oxygen saturation. In the test, an excess of manganese(II) salt, iodide (I − ) and hydroxide (OH − ) ions are added to a water sample causing a white precipitate of Mn(OH) 2 to form.

  3. Precipitation (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Precipitation_(chemistry)

    An example would be the synthesis of Cr 3+ tetraphenylporphyrin chloride: water is added to the dimethylformamide (DMF) solution in which the reaction occurred, and the product precipitates. [10] Precipitation is useful in purifying many other products: e.g. , crude bmim -Cl is taken up in acetonitrile , and dropped into ethyl acetate , where ...

  4. Analysis of water chemistry - Wikipedia

    en.wikipedia.org/wiki/Analysis_of_water_chemistry

    Chemical water analysis is carried out on water used in industrial processes, on waste-water stream, on rivers and stream, on rainfall and on the sea. [1] In all cases the results of the analysis provides information that can be used to make decisions or to provide re-assurance that conditions are as expected.

  5. Qualitative inorganic analysis - Wikipedia

    en.wikipedia.org/wiki/Qualitative_inorganic_analysis

    This includes ions which form sulfides that are insoluble at high concentrations. The reagents used are H 2 S in the presence of NH 4 OH. NH 4 OH is used to increase the concentration of the sulfide ion, by the common ion effect - hydroxide ions from NH 4 OH combine with H + ions from H 2 S, which shifts the equilibrium in favor of the ionized ...

  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. Coagulation (water treatment) - Wikipedia

    en.wikipedia.org/wiki/Coagulation_(water_treatment)

    In water treatment, coagulation and flocculation involve the addition of compounds that promote the clumping of fine floc into larger floc so that they can be more easily separated from the water. Coagulation is a chemical process that involves neutralization of charge whereas flocculation is a physical process and does not involve ...

  8. Benedict's reagent - Wikipedia

    en.wikipedia.org/wiki/Benedict's_reagent

    The net reaction between an aldehyde (or an alpha-hydroxy-ketone) and the copper(II) ions in Benedict's solution may be written as: RCHO + 2 Cu 2+ + 5 OH − → RCOO − + Cu 2 O + 3 H 2 O. The hydroxide ions in the equation forms when sodium carbonate dissolves in water. With the citrate included, the reaction becomes:

  9. Sodium fusion test - Wikipedia

    en.wikipedia.org/wiki/Sodium_fusion_test

    The sodium fusion test, or Lassaigne's test, is used in elemental analysis for the qualitative determination of the presence of foreign elements, namely halogens, nitrogen, and sulfur, in an organic compound. It was developed by J. L. Lassaigne. [1] The test involves heating the sample with sodium metal, "fusing" it with the sample. A variety ...