Relating to molar mass

Fig. 4. Critical concentrations of polystyrene/toluene and polyacrylamide/water at 25 °C in relation to molar mass determined by viscometry and light scattering... 

Viscoelastic properties have been discussed in relation to molar mass, concentration, solvent quality and shear rate. Considering the molecular models presented here, it is possible to describe the flow characteristics of dilute and semi-dilute solutions, as well as in simple shear flow, independent of the molar mass, concentration and thermodynamic quality of the solvent. The derivations can be extended to finite shear, i.e. it is possible to evaluate T) as a function of the shear rate. Furthermore it is now possible to approximate the critical conditions (critical shear rate, critical rate of elongation) at which the onset of mechanical degradation occurs. With these findings it is therefore possible to tune the flow features of a polymeric solution so that it exhibits the desired behaviour under the respective deposit conditions. 

Applications Tables 6.24 and 6.25 compare various API modes in relation to molar mass and areas of application. 

Calculate Da from the empirical relation to molar mass. From Fig. 18.9b follows ... 

Note that accessibility to the solvent does not imply accessibility to the solute. As before, the species subscript i is to be understood, there being a different partition coefficient for each species. If the pores of the gel were all of uniform size and the accessibility were only a steric one, then cr would be 1 for molecules smaller than the pore size and 0 for molecules bigger. For a distribution of pore sizes, cr will vary gradually with molecular size. For similar shapes, size is related to molar mass, and for a chromatographic separation of various proteins on any particular resin a general correlation has been shown to be of the form (Cantor Schimmel 1980)... 

Osmotic pressure is related to molar mass of the solute the smaller the mass, the higher will be the pressure at the same concentration. Electrolytes show higher osmotic pressure than nonelectrolytes because each ion affects the chemical potential of a solvent. 

What are dispersion forces How does the strength of dispersion forces relate to molar mass ... 

The Process of Effusion One of the early triumphs of the kinetic-molecular theory was an explanation of effusion, the process by which a gas escapes through a tiny hole in its container into an evacuated space. In 1846, Thomas Graham studied the effusion rate of a gas, the number of molecules escaping per unit time, and found that it was inversely proportional to the square root of the gas density. But, density is directly related to molar mass, so Graham s law of effusion is stated as follows the rate of ejfusion of a gas is inversely proportional to the square root of its molar mass, or... 

Questions 31 through 34 On the basis of molecular size, molecular polarity, and hydrogen bonding, predict for each pair of compounds the one that has the higher boiling point. State the reason for your choice. Assume molecular size is related to molar mass. 

Numerous methods have been established for determining the chemical composition drift in relation to molar mass distribution (6, 7]. These include... 

Solution activity data obtained by osmometry on dilute solutions showed that the second virial coefficient is dependent on molar mass, contradicting the Flory-Huggins theory. These problems arise from the mean-field assumption used to place the segments in the lattice. In dilute solutions, the polymer molecules are well separated and the concentration of segments is highly non-uniform. Several scaling laws were therefore developed for dilute (c < c is the polymer concentration in the solution, c is the threshold concentration for molecular overlap) and semi-dilute (c > c ) solutions. In a good solvent the threshold concentration is related to molar mass as follows ... 

The osmotic pressure (77) of dilute solutions is related to molar mass according to the following expression ... 

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