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Volume similarity

We see that, for a given pressure and temperature, the greater the molar mass of the gas, the greater its density. Equation 10 also shows that, at constant temperature, the density of a gas increases with pressure. When a gas is compressed, its density increases because the same number of molecules are confined in a smaller volume. Similarly, heating a gas that is free to expand at constant pressure increases the volume occupied by the gas and therefore reduces its density. The effect of temperature on density is the principle behind hot-air balloons the hot air inside the envelope of the balloon has a lower density than that of the surrounding cool air. Equation 10 is also the basis for using density measurements to determine the molar mass of a gas or vapor. [Pg.274]

As equation 3.3.48 indicates, the change in X is directly proportional to the extent of reaction per unit volume. Similarly, the change in X between times zero and infinity is given by... [Pg.60]

Typically, the components within the can are gaseous at most temperatures. The typical volume of an aerosol can is about 0.3 dm3 (3 x 10-4 m3), so it could contain very little gas if stored at normal pressure. But if we purchase a canister of gas and release its entire contents at once, the gas would occupy a volume similar that of... [Pg.23]

The three-arm star polymers are recognized by the UV-Vis spectrum typical of the Ru2+ complex as well as by their SEC elution volume. Similar trifunctional complexes with Ni2+ and Co2+ are labile, subject to rapid exchange. In fact, SEC experiments show that the dissociated form is the dominant eluting species. A... [Pg.86]

This was done by Hughes et al. (H7). They found that for small chamber volumes and small flow rates, the bubble volume is virtually independent of the chamber volume. Similar is the case when the chamber volume is large and the flow rates are normal. At very small flow rates and large chamber volumes, the bubbles normally form in doublets, and triplets and their size cannot be definitely determined. These conclusions have been verified by Davidson and Amick (D5) who varied the chamber volume in their equipment from 4 cm3 to 4000 cm3. [Pg.269]

Davidson and Schuler (D8), however, find that under the conditions of constant flow, surface tension has no effect on the bubble volume. Similar results are reported by Siemes and Kaufmann (SI 1). Kumar and Kuloor (K16) predicted that the surface tension effects are large at low flow rates and continuously diminish as the flow rate is increased. [Pg.272]

A considerable amount of contradiction exists regarding the influence of this variable. Schurmann (S6), while studying bubble formation in various liquids from porous earthenware, concluded that viscosity is the principal factor which determines the bubble volume. Similar conclusions have been drawn by Davidson and Schuler (D8), who find that an increase in viscosity causes a marked increase in the bubble size. [Pg.272]

When all the phases present were identified, we can quantify their volume fraction in the analyzed volume similarly to the way the Rietveld-method is used for phase analysis in XRD. A whole profile fitting is used in ProcessDifraction, modeling background and peak-shapes, and fitting the shape parameters, thermal parameters and volume fractions. Since the kinematic approximation is used for calculating the electron diffraction intensities, the grain size of both phases should be below 10 nm (as a rule of... [Pg.215]

The GPC of a local crude (Bryan, Texas) sample spiked with a known mixture of n-alkanes and aromatics is shown in Figure 5 and the GPC of the crude is shown in Figure 6. The hydrocarbon mixture is used to calibrate the length of the species which separates as a function of retention volume. Ttie molecular length is expressed as n-alkane carboa units although n-alkanes represent only a fraction of the hydrocarbons in the crude. In addition to n-alkanes, petroleum crude is composed of major classes of hydrocarbons such as branched and cyclic alkanes, branched and cyclic olefins and various aromatics and nonvolatiles namely asphaltenes. Almost all of the known aromatics without side chains elute after n-hexane (Cg). If the aromatics have long side chains, the linear molecular size increases and the retention volume is reduced. Cyclic alkanes have retention volumes similar to those of aromatics. GPC separates crude on the basis of linear molecular size and the species are spread over 10 to 20 ml retention volume range and almost all of the species are smaller than the polystyrene standard (37A). In other words, the crude has very little asphaltenes. The linear... [Pg.263]

Those characteristics of the chromatogram that have theoretical significance will be discussed later, but some common measurements that can be taken from the chromatogram are given now. The elapsed time between the dead point and the peak maximum is called the retention time, and the time between the dead point and the peak maximum the adjusted retention time. If the retention time is multiplied by the mobile phase flow-rate, the product is called the retention volume. Similarly, multiplying the adjusted retention time by the flow-rate gives the adjusted retention volume. [Pg.12]

Haematological changes in male B6C3Fi mice exposed to 62.5, 200 or 625 ppm [138, 440 or 1380 mg/ni ] butadiene for 6 h per day on five days per week for 40 weeks included decreased red blood cell count, haemoglobin concentration and packed red cell volume and increased mean corpuscular volume. Similar changes occurred in female mice exposed to 625 ppm butadiene (for details, see Section 3.1.1) (Melnick et al., 1990). [Pg.164]

The density of coal shows a notable variation with rank for carbon content (Figure 6.1) and, in addition, the methanol density is generally higher than the helium density because of the contraction of adsorbed helium in the coal pores as well as by virtue of interactions between the coal and the methanol, which results in a combined volume that is notably less than the sum of the separate volumes. Similar behavior has been observed for the water density of coals having 80 to 84% w/w carbon. [Pg.114]

Molecular modeling of compounds tested shows molecular volumes similar to those of strigolactones25 and fits into the same hypothetic receptor s cavity. No correlation between the activity and changes in molecular properties such as dipole moments or heat of formation could be established. [Pg.153]

Time is an abstract non-spatial construct, but humans often adapt spatial structures to convey temporal information (e.g., spatial metaphors, charts, and graphs see Tversky, this volume). Similarly, signers adapt signing space to express temporal information both at the lexical level and at the discourse level (see also Kita, this volume, for a discussion of how the gesture space of speakers is used to represent temporal information). [Pg.156]

Sodium Phosphate Buffer Solution Dissolve 10.4 g of monobasic sodium phosphate (NaH2P04-H20) in 500 mL of sterile, deionized water in a 1000-mL volumetric flask, and dilute to volume. Similarly, dissolve 9.465 g of anhydrous dibasic sodium phosphate (Na2HP04) in sterile, deionized water, and dilute to 1000 mL. Mix 815 mL of the monobasic sodium phosphate solution with 185 mL of the dibasic sodium phosphate solution. Adjust the pH of the buffer to 6.2 when checking the pH, use an aliquot of the buffer to prevent contamination of the solution. Adjust the pH by adding more monobasic or dibasic sodium phosphate solution as needed. The buffer solution may be stored under refrigeration for up to 1 month. [Pg.916]

For the two-dimensional case considered in the preceding, one linear condition defines a line which divides the plane into two half-planes. For a three-dimensional case, one linear condition defines a set plane which divides the volume into two half-volumes. Similarly, for an n-dimensional case, one linear condition defines a hyperplane which divides the space into two halfspaces. [Pg.382]

Formaldehyde (CH20) is sometimes released from foamed insulation used in homes. The federal standard for the allowable amount of CH20 in air is 1.0 ppbv (parts per billion volume similar to ppmv as defined in Exercise 91). How many molecules per cubic centimeter is this at STP If the concentration of formaldehyde in a room is 1.0 ppbv, what total mass of formaldehyde is present at STP if the room measure 18.0 ft X 24.0 ft X 8.0 ft ... [Pg.185]

Both calcination and hydrothermal treatment results in decrease in lowering of specific surface area and pore volume. Similarly, in the both cases some part of small pores disappears as a result of connecting. Therefore one can observe decrease in specific surface area and pore volume of micro- and mesopores (range 2-10 nm) and increase in specific surface area and pore volume of mesopores (10-50 nm) and macropores. [Pg.399]


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See also in sourсe #XX -- [ Pg.33 ]




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Volume dependence similarity principles

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