Concentration weight

Concentration is often expressed as a weight of solute in a unit volume of solution for example, gdm, or %w/v, which is the number of grams of solute in f 00 cm of solution. This is not an exact method when working at a range of temperatures, since the volume of the solution is temperature-dependent and hence the weight concentration also changes with temperature. 

Whenever a hydrated compound is used, it is important to use the correct state of hydration in the calculation of weight concentration. Thus 10%w/v CaCl2 (anhydrous) is approximately equivalent to 20% w/v CaCl2 6H2 0 and consequently the use of the vague statement 10% calcium chloride could result in gross error. The SI unit of weight concentration is kg m which is numerically equal to g dm.  

---

Figure C2.1.5. Reduced osmotic pressure FT / (RTc as a function of the weight concentration c of polystyrene (M = 130 000 g mor ) in cyclohexane at different temperatures. At 7"= 35 °C and ambient pressure, tire solution is at tire 0 conditions. (Figure from 1741, reprinted by pennission of EDP Sciences.)...

Figure C2.1.8. Reduced osmotic pressure V l(RTc as a function of the polymer weight concentration for solutions of poly(a-metliylstyrene) in toluene at 25 °C. The molecular weight of poly(a-metliylstyrene) varies...

Anotlier simple way to obtain the molecular weight consists of measuring tire viscosity of a dilute polymer solution. The intrinsic viscosity [q] is defined as tire excess viscosity of tire solution compared to tliat of tire pure solvent at tire vanishing weight concentration of tire polymer [40] ... 

Molal concentration of ammonia in the solutions in percentages (Weight concentration of ammonia in die solution in percentages)... 

Moisture measurements are important in the process industries because moisture can foul products, poison reactions, damage equipment, or cause explosions. Moisture measurements include both absolute-moisture methods and relative-humidity methods. The absolute methods are those that provide a primaiy output that can be directly calibrated in terms of dew-point temperature, molar concentration, or weight concentration. Loss of weight on heating is the most familiar of these methods. The relative-humidity methods are those that provide a primaiy output that can be more direc tly calibrated in terms of percentage of saturation of moisture. 

Here Yi and y2 are the activity coefficients of ions in solution, y, and y2 are the coefficients of resin activity, cx and c2 are ion concentrations in solution, ntj and m2 are fixed ion concentrations (exchange or weight concentrations) and Ks is the concentration constant of ion exchange, the selectivity constant. 

Equation (3.14.2.11) predicts the cell dry weight concentration with respect to time. The model shows the cell dry weight concentration (x) is independent of substrate concentration. However, the logistic model includes substrate inhibition, which is not clearly seen from Equation (3.14.2.11). 

Fig. E.9.2. Cell dry weight concentration versus dilution rate in a CSTR bioreactor.

Table E.10.2. Natural logarithm of the cell dry weight concentration...

Fig. 13-3 Precipitation-weighted concentration of SO4 (mg/L) over North America for 1987.

Hashimoto T., Shibayama M., and Kawai H., Ordered structure in block copolymer solution. 4. Scaling rules on size of fluctuations with block molecular weight, concentration temperature in segregation and homogeneous regimes. Macromolecules, 16, 1093, 1983. 

Figure 3. Weighted concentration of effective strands for a typical polyol-urethane coating using the kinetics of Figure 2.

Figure 4. Weighted concentration of effective strands versus humidity at constant cure time for different initial ratios of isocyanate to hydroxy. The cure time is chosen so that at equal isocyanate and hydroxy and H=0, the extent of reaction is 85%.

Figure 5. Weighted concentration of effective strands versus bake temperature for a typical high solids polyol crosslinked with hexamethoxymethylmelamine. The ratio of methoxy to hydroxy groups is given by "R". For the dashed lines, the extent of methoxy self-condensation is assumed to be zero. The solid lines use the self-condensation data of T. Nakamichi, Prog. Org. Coat., 14, 23 (1986).

THIS CROSSLINK DENSITY IS CALLED THE WEIGHTED CONCENTRATION OF" EFFECTIVE STRANDS. ... 

PRINT "THE WEIGHT CONCENTRATION OF EFFECTIVE STRANDS -" LINK 3350 PRINT 3360 PRINT 3370 GOTO 2220... 

---