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The yellow complex Rh(PPh 3) 3 (NCO) and orange complex Rh(PPh 3) 3 (OCN) are linkage isomers and show differences in their infrared spectra which can be used for diagnosis. [15] The cyanate ion can bridge between two metal atoms by using both its donor atoms. For example, this structure is found in the compound [Ni 2 (NCO) 2 2](BPh 4) 2. In ...
2OC(NH 2) 2 + Na 2 CO 3 → 2Na(NCO) + CO 2 + 2NH 3 + H 2 O. Sodium allophanate is observed as an intermediate: [2] H 2 NC(O)NHCO 2 Na → NaOCN + NH 3 + CO 2. It can also be prepared in the laboratory by oxidation of a cyanide in aqueous solution by a mild oxidizing agent such as lead oxide. [3]
Reference ranges (reference intervals) for blood tests are sets of values used by a health professional to interpret a set of medical test results from blood samples. Reference ranges for blood tests are studied within the field of clinical chemistry (also known as "clinical biochemistry", "chemical pathology" or "pure blood chemistry"), the ...
The value of each log D is then determined as the logarithm of a ratio—of the sum of the experimentally measured concentrations of the solute's various forms in one solvent, to the sum of such concentrations of its forms in the other solvent; it can be expressed as [10]: 275–8
Once the presence of certain substances in a sample is known, the study of their absolute or relative abundance could help in determining specific properties. Knowing the composition of a sample is very important, and several ways have been developed to make it possible, like gravimetric [3] and volumetric analysis. Gravimetric analysis yields ...
In chemistry, the amount of substance (symbol n) in a given sample of matter is defined as a ratio (n = N/N A) between the number of elementary entities (N) and the Avogadro constant (N A). Since 2019, the value of the Avogadro constant N A is defined to be exactly 6.022 140 76 × 10 23 mol −1 .
The conversion between hydroxyl value and other hydroxyl content measurements is obtained by multiplying the hydroxyl value by the factor 17/560. [2] The chemical substance may be a fat, oil, natural or synthetic ester, or other polyol. [3] ASTM D 1957 [4] and ASTM E222-10 [5] describe several versions of this method of determining hydroxyl value.
R 2 NC(O)N(H)R' + R''NCO → R 2 NC(O)NR'C(O)NHR'' Reaction between a di-isocyanate and a compound containing two or more amine groups produces long polymer chains known as polyureas. Carbodiimides are produced by the decarboxylation of alkyl and aryl isocyanate using phosphine oxides as a catalyst: [13] C 6 H 11 NCO → (C 6 H 11 N) 2 C + CO 2