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When there is no public data on the element in its pure form, price of a compound is used, per mass of element contained. This implicitly puts the value of compounds' other constituents, and the cost of extraction of the element, at zero.
Then, the output is translated into the "language" of common use: molar and mass concentrations, alkalinity, buffer capacities, water hardness, conductivity and others. History. Version 1.0 was released in January 2012 (after a half-year test run in 2011). The project is active with 1-2 updates per month.
The molar ionic strength, I, of a solution is a function of the concentration of all ions present in that solution. [3]= = where one half is because we are including both cations and anions, c i is the molar concentration of ion i (M, mol/L), z i is the charge number of that ion, and the sum is taken over all ions in the solution.
From the weight of the sodium salt and the volume of air in the room, we easily calculate that one part by weight of air could not contain more than 1/20 millionth weight of sodium. Occurrence The Earth's crust contains 2.27% sodium, making it the sixth most abundant element on Earth and the fourth most abundant metal, behind aluminium , iron ...
It is measured by titrating the solution with an acid such as HCl until its pH changes abruptly, or it reaches a known endpoint where that happens. Alkalinity is expressed in units of concentration, such as meq/L (milliequivalents per liter), μeq/kg (microequivalents per kilogram), or mg/L CaCO 3 (milligrams per liter of calcium carbonate). [3]
Companies may use seawater for this process due to its low cost. The water used is usually brackish water or brine (i.e. a solution with >0.5% salinity). In these cases, additional contaminant chemicals may be present in the water feed. The low voltage DC current still performs electrochlorination.
A liquid fat sample combined with neutralized 95% ethanol is titrated with standardized sodium hydroxide of 0.1 eq/L normality to a phenolphthalein endpoint. The volume and normality of the sodium hydroxide are used, along with the weight of the sample, to calculate the free fatty acid value. [3]
They can be used to calculate mixed ion activity coefficients and water activities in solutions of high ionic strength for which the Debye–Hückel theory is no longer adequate. They are more rigorous than the equations of specific ion interaction theory (SIT theory), but Pitzer parameters are more difficult to determine experimentally than ...