Volume-to-mass

To convert between molarity and the other mole-based concentration measures, we must relate volume to mass and number of moles. Whereas molar mass lets us convert between mass and moles, we need density to convert... 

This type of extraction can be carried out in two different ways. A soil sample can be brought into the laboratory and extracted with relatively large amounts of water to try to determine its inorganic composition. The water-to-soil ratio can be either on a mass-to-mass basis or a volume-to-mass ratio. A one-to-one ratio is commonly used, although other ratios have been used. After a designated extraction time, with or without shaking, water is filtered from the soil and analyzed. A typical water extraction of soil is given in Procedure 11.1. 

Equation (9.3.22) can be used when volume to mass-fraction conversion is needed. In the right-hand side braces, the first term corresponds to the amount of element i entering the molten zone, the last two terms to the amount left behind at z. Assuming... 

The Effect of the Ratio of Solution Volume to Mass of Resin (V/m, mL/g)... 

To investigate the effect of ratio of solution volume to mass of solid and adsorption of metal ions 0.5 g resin samples were mixed 25-75 mL of aqueous solution of the constant initial concentration of metal ions (50 ag/mL Pb +). The pH was adjusted to 4 for adsorption of Pb +. The flasks with their contents were stirred for 4 h. 

After a period of growth, these aggregates occupy a large amount of space due to their large volume to mass ratio. The total volume fraction of all aggregates, is given by... 

Jiintgen and Heek [7] studied ethane release from a finely ground coal (19.1% volume to mass) as a function of heating rate. Their heating rates were between 10 and 10 K/min. 

When reactants are liquids, they are almost always measured by volume. So, to do calculations involving liquids, you add two more steps to the sequence of mass-mass problems—the conversions of volume to mass and of mass to volume. Five conversion factors—two densities, two molar masses, and a mole ratio—are needed for this type of calculation, as shown in Skills Toolkit 4. 

To convert from volume to mass or from mass to volume of a substance, use the density of the substance as the conversion factor. Keep in mind that the units you want to cancel should be on the bottom of your conversion factor. 

In several papers, catalytic activities arc quoted in units such as gm min i, which are ambiguous if the volume of gas is not given. To prevent unwarranted comparisons between different researches, such activities are given here as 2.0 x 10 (V/M) cm gm min to indicate that the ratio of volume to mass or volume to area (V/A) is not given in the original. 

Volume is written to 3 significant figures, such as 1.00 cc, to match the 3 significant figures in the mass. As conversion factors, densities can be used to convert a known volume to mass or a known mass to volume. 

Using the density as a conversion factor from volume to mass, we have m = (10.0jnfc+Ig)(l3.6- j Cancellation of units results in ... 

In the following vehicle test study catalysts with a 100 g Pd/ft loading were used. For the three different vehicles chosen the ratio of catalyst volume to mass of the vehicle varied from 1.4 liter catalyst/ton vehicle (A) over 2.1 1/t (B) to 2.6 1/t (C). FTP 75 tests were conducted for the fresh and 50 h, 900°C, fuel cut aged systems. The conversion rates for CO, HC and NO are given in Figure 9. 

Dependent on the ratio of catalyst volume to mass of the vehicle conversion rates exceeding 90 % for all pollutants were achieved after severe engine aging. 

To determine the moles of water present, we first convert volume to mass using the density ... 

To obtain surface growth rates we differentiate the volume fraction curves, converting volume to mass using a density of 1.8 g/cm. Although all the curves appear to have similar slopes... 

Tamped Density and Tamped Volume (ISO 787, Part II). The tamped density is the ratio of mass to volume, while the tamped volume is the ratio of volume to mass after tamping under specified conditions. These quantities provide information about the volume requirements of the products. 

Table 8.A.2 Conversion factors linking volume to mass for bitumen at various temperatures and s gravities ipecific...

Density can be used as a conversion factor from mass to volume or from volume to mass. To convert between volume and mass, use density directly. To convert between mass and volume, invert the density. 

Intrinsic viscosity [ /] is a physical property (expressed in dL/g), which in essence is the ratio of volume to mass. As the generation number increases and transition occurs to a spherical shape, the volume of a spherical dendrimer increases in cubic fashion while its mass increases exponentially hence, the value of [//] must decrease once a certain generation is reached. This prediction has now been confirmed for many different dendrimer families [9, 116, 179]. Because of this feature, the soft particle dendron/dendrimer-based, [S-l]-type nano-elements are unique macromolecules that exhibit completely different physico-chemical properties (i.e., nano-periodic property patterns) compared to compositionaUy... 

An excess amount of ice is placed in a calorimeter (polystyrene cup) with a known amount of hot water. Enough time is allowed for the ice to melt to bring the temperature of the ice-water to the melting point of ice, approximately 0 C. At this time the extra ice is removed. The volume of the melted ice and water in the cup will be used with temperature data for the calorimeter to calculate the molar heat of fusion of ice. The density of water (1.00gcm ) will be used to convert volume to mass where needed. 

Conversions from volume to mass and vice versa have to be frequently made, so that all measuring parameters such as product level, water interface, density, and temperature measimements are equally important. 

Level gauging instruments measure the liquid level in the tank. Pressure transmitters measure the hydrostatic pressure of the liquid column. Both level and pressure are primary functions for the calculation of volume and mass, respectively. Hybrid sj stems, such as HIMS, use both inputs in one system. Conversions from volume to mass or vice versa are made using density and temperature as secondary inputs. The density input may be obtained from an outside source, such as a laboratory, or may be measured in the tank by using pressvue transmitters or servo density. The temperature input is obtained from a temp ature-measuring system in the tank. 

As always, the required conversions can be combined into a single line calculation. However, it is instructive to break the calculation into three steps (1) a conversion from volume to mass, (2) a conversion from mass to amount in moles, and (3) a conversion from amount in moles to molecules. These three steps emphasize, respectively, the roles played by density, molar mass, and the Avogadro constant in the conversion pathway. (See Table 3.1.)... 

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