Solutions 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. 

Measure the volumes of sucrose solution and water consumed. Calculate the preference for the sucrose solution as a percentage of total liquid consumed and total sucrose intake in mg/g body weight. In addition, commercially available automated lick-counters (lickometers) may be used (e.g., by Lafayette Instrument Co, Lafayette IN, United States or Columbus Instruments, Columbus OH, United States). Assess the number of licks at each bottle for the duration of the test (i.e., 24-72 h) per 100 mg of body weight, and the preference for sucrose as a percentage of total licks (23, 27, 28) (see Notes 4-6). 

When the hydrochloric acid has cooled to room temperature determine the volume and the specific gravity of the solution in both absorption bottles. Use either a hydrometer or the apparatus shown in Fig. 19. Consult the table on page 371 and determine the percentage composition of the preparation. Calculate the weight of hydrogen chloride obtained, the normality of the solution, and the percentage yield. 

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. 

Reliable pH data and activities of ions in strong electrolytes are not readily available. For this reason calculation of corrosion rate has been made using weight-loss data (of which a great deal is available in the literature) and concentration of the chemical in solution, expressed as a percentage on a weight of chemical/volume of solution basis. Because the concentration instead of the activity has been used, the equations are empirical nevertheless useful predictions of corrosion rate may be made using the equations. 

Figure 9. Effect of enzyme components from T. koningii cellulose on the formation of alkali-soluble cellulose from cotton fiber. A reaction mixture consisting of 200 mg of cotton, 2 mL of 0.2 M acetate buffer, pH 4.5, enzyme, water, and NaNs solution to give a total volume of 10 mL, was incubated at 50°C for various times. Percentage hydrolysis was calculated from the loss in weight determined on weighed crucibles. The fraction soluble in alkali (10% NaOH) was determined in a similar fashion after incubating for 3 hr at 25°C. Ct ( - 0) Cx + /3-glucosidase ( - ) ...

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