Search results
Results From The WOW.Com Content Network
Fluorescein aqueous solutions, diluted from 10,000 to 1 parts-per-million in intervals of 10 fold dilution. At 1 ppm the solution is a very pale yellow. At 1 ppm the solution is a very pale yellow. As the concentration increases the colour becomes a more vibrant yellow, then orange, with the final 10,000 ppm a deep red colour.
As an example, a measured NO x concentration of 45 ppmv in a dry gas having 5 volume % O 2 is: 45 × ( 20.9 - 3 ) ÷ ( 20.9 - 5 ) = 50.7 ppmv of NO x. when corrected to a dry gas having a specified reference O 2 content of 3 volume %. Note: The measured gas concentration C m must first be corrected to a dry basis before using the above equation.
For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O 2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2.
The same direct relationship applies to gases and vapors diluted in air for example. Although, thorough mixing of gases and vapors may not be as easily accomplished. [citation needed] For example, if there are 10 grams of salt (the solute) dissolved in 1 litre of water (the solvent), this solution has a certain salt concentration . If one adds ...
In chemistry, the mass fraction of a substance within a mixture is the ratio (alternatively denoted ) of the mass of that substance to the total mass of the mixture. [1] Expressed as a formula, the mass fraction is:
Its units are in parts per million (ppm) for gases and in milligrams per cubic meter (mg/m 3) for particulates such as dust, smoke and mist. The basic formula for converting between ppm and mg/m 3 for gases is ppm = (mg/m^3) * 24.45 / molecular weight. This formula is not applicable to airborne particles.
The following formulas can be used to calculate the volumes of solute (V solute) and solvent (V solvent) to be used: [1] = = where V total is the desired total volume, and F is the desired dilution factor number (the number in the position of F if expressed as "1/F dilution factor" or "xF dilution"). However, some solutions and mixtures take up ...
Carbonate hardness, is a measure of the water hardness caused by the presence of carbonate (CO 2− 3) and bicarbonate (HCO − 3) anions. Carbonate hardness is usually expressed either in degrees KH (from the German "Karbonathärte"), or in parts per million calcium carbonate ( ppm CaCO 3 or grams CaCO 3 per litre|mg/L).