Weight to volume percent

Weight percent (% w/w), volume percent (% v/v) and weight-to-volume percent... 

The units of concentration most frequently encountered in analytical chemistry are molarity, weight percent, volume percent, weight-to-volume percent, parts per million, and parts per billion. By recognizing the general definition of concentration given in equation 2.1, it is easy to convert between concentration units. 

X-ray diffraction (XRD) results are provided in Table 111 in weight percent. Table IV provides results of Si content in volume percent from three different measurements, namely (1) calculation from density. (2) measured by XRD and converted from weight to volume percent and (3) measured by quantitative image analysis (QIA). In all cases, the amount of carbon in the starting preforms, with similar starting SIC weights, increases as the sample number increases. 

Liquid solute and volume percent Solid solute and weight to volume percent Solid solute and molarity... 

Formally, percent by weight to volume is defined as grams of solute per 100 mL of solution. There are two mathematically equivalent statements of this definition ... 

Percent by Weight (% w/w) Percent by weight is commonly reported by chemical analysts. The definition of percent by weight is exactly analogous to the definition of percent weight to volume, except the denominator expresses the quantity of solution in terms of grams, not milliliters. 

To relate percent by weight to percent weight to volume, we again need to employ the density of the solution. For example, what is the percent by weight of a D5W solution The density of D5W is 1.0157 g/mL. Let s see we need to convert 5.0 g per 100 mL into grams per 100 g. That is, we need to convert the denominator from 100 mL into 100 g. Density is the quantitative relationship between mass and volume. So, let s apply the density as a conversion factor to convert the amount of solution from milliliters into grams. You will find this solution is 4.9% (w/w) glucose. 

Water absorption showed a rather complex quantitative pattern for composites of HDPE, wood flour, and talc. Evidently, the higher the plastic content and the talc content, the lower the water absorption. However, in the triple system when talc also replaced plastic, and wood fiber content increased, the relationship with water absorption was not that simple, particularly when weight and volume percents of the ingredients were considered. For example, after 4000 h of water immersion, the composition of 44% HDPE, 27% wood flour, and 27% talc (the balance was a lubricant) absorbed 6% water (w/w). A slight increase of HDPE content to 47%, with a concurrent increase of wood flour to 40% and decrease of talc content to 10% gave 11% of water absorption. A sharp decrease of HDPE content to 25%, with both a concurrent decrease of wood flour (36%) and increase in talc (36%) resulted in 13% of water absorption. Finally, a composition with 28% of HDPE, 54% of wood flour, and 14% of talc absorbed 20% of water [6-8]. 

The output of a chromatographic instrument can be of two types (1) A plot of area retention time versus detector response. The peak areas represent the amount of each component present in the mixture. (2) A computer printout giving names of components and the concentration of each in the sample. The units of concentration are reported in several ways as weight percent or ppm by weight, as volume percent or ppm by volume, or as mole percent. Refer to Chromatography, (Source Cheremisinoff, N.P. Polymer Characterization Laboratory Techniques and Analysis, Noyes Publishers, New Jersey, 1996). 

It is necessary to change the weight percent concentration to volume percent in order to calculate the cake and filtrate volumes. One kilogram of su ension at 10 wt% soMs contains 0.1 kg of solids and 0.9 kg of liquid. The volume of the suspension is ... 

A sample of an ore was analyzed for Cu as follows. A 1.25-g sample of the ore was dissolved in acid and diluted to volume in a 250-mb volumetric flask. A 20-mb portion of the resulting solution was transferred by pipet to a 50-mb volumetric flask and diluted to volume. An analysis showed that the concentration of Cu in the final solution was 4.62 ppm. What is the weight percent of Cu in the original ore ... 

Another phenomenon is the increase in power required with percent sohds, which makes a dramatic change at approximately 40 percent by volume, and then dramatically changes again as we approach the ultimate weight percent of settled solids. This phenomenon is covered by Oldshue (op. cit.), who describes conditions required for mixing slurries in the 80 to 100 percent range of the ultimate weight percent of settled sohds. 

Assume a continuous release of pressurized, hquefied cyclohexane with a vapor emission rate of 130 g moLs, 3.18 mVs at 25°C (86,644 Ib/h). (See Discharge Rates from Punctured Lines and Vessels in this sec tion for release rates of vapor.) The LFL of cyclohexane is 1.3 percent by vol., and so the maximum distance to the LFL for a wind speed of 1 iti/s (2.2 mi/h) is 260 m (853 ft), from Fig. 26-31. Thus, from Eq. (26-48), Vj 529 m 1817 kg. The volume of fuel from the LFL up to 100 percent at the moment of ignition for a continuous emission is not equal to the total quantity of vapor released that Vr volume stays the same even if the emission lasts for an extended period with the same values of meteorological variables, e.g., wind speed. For instance, in this case 9825 kg (21,661 lb) will havebeen emitted during a 15-min period, which is considerablv more than the 1817 kg (4005 lb) of cyclohexane in the vapor cloud above LFL. (A different approach is required for an instantaneous release, i.e., when a vapor cloud is explosively dispersed.) The equivalent weight of TNT may be estimated by... 

Step I. To determine the percent by weight of calcium or of sodium chloride in the internal phase, locate the intersection of the line drawn horizontally from the cm of strong silver nitrate required to titrate 1 cm of whole mud with the line projected vertically from the volume percent of fresh water by retort. 

Step 5. After having found the adjusted mud weight, proceed horizontally from that point to the right to determine the volume percent of solids occupied by the basic emulsifier package. The volume percent of suspended solids is 100% less the sum of the volume-percent oil, the true volume-percent brine (Step 2), and the volume-percent emulsifier solids. 

Find the adjusted mud weight value, extend that point downward until it meets the volume-percent suspended solids line. Proceed horizontally to find the ppg of low gravity solids. 

---