Pound mol

Typical units for local rates of production or reaction are [mole/cm s] for homogeneous reactions and [mole/cm s] for heterogeneous ones. Various multiples of the SI unit mol (gram-mol) are common, such as kmol (kilogram-mol) and lb-mol (pound-mol), though in view of metrication, use of the latter unit is discouraged. 

A column of hot air (flg. 7.1) weighs less than an equally tall column of cold air, which is shown dotted to form a U-tube manometer. The dotted column corresponds to the atmosphere outside a stack or chimney. The difference in weights of the columns creates a pressure difference (AP) known as draft (see glossary), expressed in inches or millimeters of water column on a manometer. The draft is proportional to the height of the gas column and to the difference in densities of the hot and cold gas columns. The densities of air and other gases depend on their pressures and temperatures, thus density, p = p/RT, where density is pounds per cubic foot (US) or kg/m (SI), T is absolute temperature rankine (US) or kelvin (SI), and P is a constant = 53.3 fp/pound mol °R for air (US), or 287 joules-kg-mol °K for air (SI). Densities are tabulated in references 51 and 52. 

The pound-mol (Ib-mol) is the analogous unit in the American Engineering system and represents an amount of matter equal to the molecular weight expressed in Ibm. The relationship between the mol and Ib-mol is... 

The number of pound-mols is equal to the weight of the gas divided by the molecular weight of the gas. Therefore, we write the Ideal Gas Law as ... 

In U.S. engineering work the unit of mass is the pound mass, written Ibm. We regularly use the pound mol written... 

The overdot indicates a flowrate. For systems with only one chemical species we usually use Eqs. 2.5 and 2.6 as written. However, in chemical engineering we very often deal with mixtures and with chemical reactions. For those we usually choose our unit of mass as one mol or one pound mol (Ibmol) (=454 mol). The relation between mass and mols, referred to often in this book, is given by Eq. 1.5. If we solve that equation for m, and substitute everywhere in Eqs. 2.5 and 2.6, we find that all the Ms cancel, and we have the same equations for mols, with m,s replaced by n s. However, mols are not conserved. For example, in the reaction... 

Tables of thermodynamic properties are always in terms of specific properties (properties per Ibm, or kg, or per mol). For systems that involve only one chemical species (e.g., steam power plants, refrigerators, the other systems in ME thermodynamics), the equations and tables are all per unit mass (Ibm or kg). However, in chemical engineering thermodynamics, which deals with mixtures and with chemical reactions, we most often choose our unit of mass as one mol or one pound mol.

In this example addition to the double bond of an alkene converted an achiral mol ecule to a chiral one The general term for a structural feature the alteration of which introduces a chirality center m a molecule is prochiral A chirality center is introduced when the double bond of propene reacts with a peroxy acid The double bond is a prochi ral structural unit and we speak of the top and bottom faces of the double bond as prochiral faces Because attack at one prochiral face gives the enantiomer of the com pound formed by attack at the other face we classify the relationship between the two faces as enantiotopic... 

Wo = Mols liquid mixture originally charged to still pot w = Pounds coolant per hour... 

Adkins, J.N., Vamum, S.M., Auberry, K.J., Moore, R.J., Angell, N.H., Smith, R.D., Springer, D.L., Pounds, J.G. (2002). Toward a human blood serum proteome analysis by multidimensional separation coupled with mass spectrometry. Mol. Cell. Proteomics 1,47-955. 

Note Because there is a constant conversion factor between grams and pounds, we can work totally in pounds. Since the formula weights are CuFeS2 (183.5 g/mol), Cu2S (159.2 g/mol) and Cu (63.55 g/mol), we have... 

The best candidate for a strong fiber was the polymer made from p-phenylene-diamine and terephthalic acid, and it eventually became the basis for Kevlar. It was very difficult to spin Kevlar into fibers, until the discovery that it forms a crystalline complex with sulfuric acid at a ratio of 1 mol Kevlar to 5 mol sulfuric acid. This enabled fiber spinning at high polymer concentrations. After spinning, it is necessary to get rid of the sulfuric acid by reaction with lime, to produce 7 lbs of gypsum per pound of fiber. By 1972, they completed a 1 million pound market development plant, and by 1982 they reached full commercialization with a 45 million pound plant. 

MOLE (mol). A unit of amount of substance. One mole is an amount of a substance, in specified mass units, equal to the molecular weight of that substance. (The SI unit for amount of substance. Examples are the gram mole or the pound mole.)... 

FIG. 14-9 O Connell correlation for overall column efficiency for absorption. H is in lb mol/(atm-ft3), P is in atm, and ]l is in cP. To convert HP/[i in pound-moles per cubic foot-centipoise to kilogram-moles per cubic meter-pascal-second, multiply by 1.60 x 104. [O Connell, Trans. Am. Inst. Chem. Eng., 42,... 

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