enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    For gases, volume percent = mole percent 1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10 6 . Care must be taken with the concentrations expressed as ppbv to differentiate between the British billion which is 10 12 and the USA billion which is 10 9 (also referred to as the long scale and ...

  3. Useful conversions and formulas for air dispersion modeling

    en.wikipedia.org/wiki/Useful_conversions_and...

    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.

  4. Amine value - Wikipedia

    en.wikipedia.org/wiki/Amine_value

    It is the number of Nitrogens x 56.1 (Mwt of KOH) x 1000 (convert to milligrams) divided by molecular mass of the amine functional compound. So using Tetraethylenepentamine (TEPA) as an example: Mwt = 189, number of nitrogen atoms = 5 So 5 x 1000 x 56.1/189 = 1484. So the Amine Value of TEPA = 1484

  5. Mass fraction (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Mass_fraction_(chemistry)

    Mass fraction can also be expressed, with a denominator of 100, as percentage by mass (in commercial contexts often called percentage by weight, abbreviated wt.% or % w/w; see mass versus weight). It is one way of expressing the composition of a mixture in a dimensionless size ; mole fraction (percentage by moles , mol%) and volume fraction ...

  6. Hydroxyl value - Wikipedia

    en.wikipedia.org/wiki/Hydroxyl_value

    In analytical chemistry, the hydroxyl value is defined as the number of milligrams of potassium hydroxide (KOH) required to neutralize the acetic acid taken up on acetylation of one gram of a chemical substance that contains free hydroxyl groups.

  7. Acid value - Wikipedia

    en.wikipedia.org/wiki/Acid_value

    In chemistry, acid value (AV, acid number, neutralization number or acidity) is a number used to quantify the acidity of a given chemical substance.It is the quantity of base (usually potassium hydroxide (KOH)), expressed as milligrams of KOH required to neutralize the acidic constituents in 1 gram of a sample.

  8. Equivalent (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Equivalent_(chemistry)

    An equivalent (symbol: officially equiv; [1] unofficially but often Eq [2]) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount (typically one mole) of another substance in a given chemical reaction.

  9. Mass concentration (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Mass_concentration_(chemistry)

    In chemistry, the mass concentration ρ i (or γ i) is defined as the mass of a constituent m i divided by the volume of the mixture V. [1]= For a pure chemical the mass concentration equals its density (mass divided by volume); thus the mass concentration of a component in a mixture can be called the density of a component in a mixture.