Weight/volume percentage

A 25.00-mL sample of a household cleaning solution was diluted to 250.0 mL in a volumetric flask. A 50.00-mL aliquot of this solution required 40.38 mL of 0.2506 M HCl to reach a bromocre-sol green end point. Calculate the weight/volume percentage of NH3 in the sample. (Assume that all the alkalinity results from the ammonia.)... 

For very dilute solutions, solubility is often expressed in units of parts per million (ppm), which is defined as the quantity of solute dissolved in 1,000,000 equivalent units of solution. As long as the same unit is used for both solute and solvent, the concentration in parts per million is equivalent to the weight, volume, or weight-volume percentages multiplied by 10,000. The descriptive terms of solubility that is expressed in units of parts of solvent required for each part of solute can be found in each edition of the United States Pharmacopeia (Table 1). 

Weight percentage is the easiest percentage solution to make, but sometimes you may need to know the volume of the solution. In this case, you can use the weight/volume percentage. 

Weight/volume percentage is very similar to weight/weight percentage, but instead of using grams of solution in the denominator, it uses milliliters of solution ... 

Since the commercial mixture A mentioned above is a complex chemical system, its critical micelle concentration (CMC) can be determined in weight/ volume percentage when the product is dissolved. Table 15.2 lists the CMC of this compound in some specific situations that represent potential sources of corrosion in the industry, that is, saline solutions and high temperatures. 

Names such as hydrobromic acid refer to an aqueous solution, and percentages such as 48% HBr denote the weight/volume of hydrogen bromide in the solution. 

Five to 10 c.c. of the oil are shaken in a Hirschsohn fiask, as used for cassia oil analysis, with a 5 per cent, solution of caustic soda, until absorption is complete, and the unabsorbed oil driven into the neck cf the flask by more of the solution and its volume read off. The difference between the original amount of oil used and the unabsorbed portion may be taken as phenols. Strictly speaking, this method gives a volume percentage, which can be converted into a weight percentage if the specific gravities of the two portions of the oil be known. 

The particle size distribution can be plotted in terms of the cumulative percent oversize or undersize in relation to the particle diameters. The weight, volume, number, and so on are used for percentage. By differentiating the cumulative distribution with respect to the diameter of the particle, the PSD can be obtained. 

Figure I Dispersibility of 50 g pectin in 10s mL water in a 2-L two-neck distilling flask held at 26°C with mild stirring. The weight per volume percentage concentration was calculated, after periodically withdrawing 10-mL samples from the suspension and oven-drying them to constant weight.

A discussion of the thermodynamics and kinetics of solubility hrst requires a discussion of the method hy which solubility is reported. The solubility of a substance may be dehned in many different types of units, each of which represents an expression of the quantity of solute dissolved in a solution at a given temperature. Solutions are said to be saturated if the solvent has dissolved the maximal amount of solute permissible at a particular temperature, and clearly an unsaturated solution is one for which the concentration is less than the saturated concentration. Under certain conditions, metastable solutions that are supersaturated can be prepared, where the concentration exceeds that of a saturated solution. The most commonly encountered units in pharmaceutical applications are molarity, normality, molality, mole fraction, and weight or volume percentages. 

The volume percentage is also the mole percentage yield, but not the weight percentage. 

Viscosity of the fumed silica, Aerosil, (from Degussa) HDDA suspension was measured on a Brookfield viscometer. The percentages are weight/volume. The Aliquat persulfate was prepared according to the procedures in 24). 1, 6 hexanediol diacrylate (HDDA) (90% technical grade) was used as received from Aldrich. 

---