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The absorbance of the blue solution can be measured with a colorimeter and the concentration of phosphate in the original solution can be calculated. Alternatively, a direct (but approximate) reading of phosphate concentration can be obtained by using a Lovibond comparator. This method for phosphate determination is known as Denigés' method ...
The values in an NPK fertilizer label are related to the concentrations (by weight) of phosphorus and potassium elements as follows: P 2 O 5 consists of 56.4% elemental oxygen and 43.6% elemental phosphorus by weight.
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid, a.k.a. phosphoric acid H 3 PO 4. The phosphate or orthophosphate ion [PO 4] 3− is derived from phosphoric acid by the removal of three protons H +.
The CMC is the concentration of surfactants in the bulk at which micelles start forming. The word bulk is important because surfactants partition between the bulk and interface and CMC is independent of interface and is therefore a characteristic of the surfactant molecule. In most situations, such as surface tension measurements or ...
In physiology, transport maximum (alternatively Tm or T max) refers to the point at which increase in concentration of a substance does not result in an increase in movement of a substance across a cell membrane. In renal physiology, the concept of transport maximum is often discussed in the context of glucose and PAH. [citation needed]
The predicted no-effect concentration (PNEC) is the concentration of a chemical which marks the limit at which below no adverse effects of exposure in an ecosystem are measured. PNEC values are intended to be conservative and predict the concentration at which a chemical will likely have no toxic effect.
The absorbance of a material that has only one absorbing species also depends on the pathlength and the concentration of the species, according to the Beer–Lambert law =, where ε is the molar absorption coefficient of that material; c is the molar concentration of those species; ℓ is the path length.
The van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass. For most non- electrolytes dissolved in water, the van 't Hoff factor is essentially 1.