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Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water.The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution.
Major dictionaries do not agree on the spelling, [1] [2] [3] giving other options of per mil, [2] per mill, [1] [3] permil, [1] [4] permill, [1] permille. [ 5 ] [ 6 ] The word promille is the cognate in Dutch, German, Finnish and Swedish, and is sometimes seen as a loanword in English with the same meaning as per mille .
Although ppmv and grains per dscf have been used in the above examples, concentrations such as ppbv (i.e., parts per billion by volume), volume percent, grams per dscm and many others may also be used. 1 percent by volume = 10,000 ppmv (i.e., parts per million by volume).
1 atm = absolute pressure of 101.325 kPa or 1.01325 bar; mol = gram mole and kmol = 1000 gram moles; Pollution regulations in the United States typically reference their pollutant limits to an ambient temperature of 20 to 25 °C as noted above. In most other nations, the reference ambient temperature for pollutant limits may be 0 °C or other ...
The equivalent weight of an element is the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. The corresponding unit of measurement is sometimes expressed as "gram equivalent". [1] The equivalent weight of an element is the mass of a mole of the element divided by the element's valence.
Toxic: a chemical that has a median lethal concentration (LC 50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats ...
The decare (daa) is a unit of area equal to 1000 m 2. The hectare (ha) is a unit of area equal to 10 000 m 2 ... The gravet is a unit of mass equal to one gram (1 g).
1795: the gram (1 / 1000 of a kilogram) was provisionally defined as the mass of one cubic centimetre of water at the melting point of ice. [12] 1799: The Kilogramme des Archives was manufactured as a prototype. It had a mass equal to the mass of 1 dm 3 of water at the temperature of its maximum density, which is approximately 4 °C. [13]