Conversion factor percent composition

In the above relationship, the left-hand side term, being ratio of two activity coefficient terms is independent of the standard state chosen. The activity coefficient (generally termed /) based on 1 weight percent solution as the standard state, can very well be used. On the right hand side, N or the mole- (or atom-) fraction, would be replaced by weight per cent of solute and the interaction coefficient would have to absorb within it the corresponding conversion factor for composition. In this form, the interaction coefficient is generally represented by the symbol e . 

Stoichiometry is the series of calculations on the basis of formulas and chemical equations and will be covered in Chapter 4. The use of conversion factors is common even when the relative proportions are not fixed by a chemical formula. Consider a silver alloy used for jewelry production. (Alloys are mixtures of metals and, as mixtures, may be produced in differing ratios of the metals.) A particular alloy contains 86 percent silver. Factors based on this composition, such as... 

However, because equation (3) and equation (4) have different units, grams versus moles, one of these equations must be changed by the use of unit conversion factors. Since the goal of this experiment is to determine the percent composition by mass, an appropriate common unit for both equations is grams. The percent composition of the two components is then calculated from the masses of the two components. 

We can use mass percent composition as a conversion factor between grams of a constituent element and grams of the compoxmd. For example, we just saw that the mass percent composition of sodium in sodium chloride is 39%. This can be written as ... 

EXAMPLE 6.8 Using Mass Percent Composition as a Conversion Factor The FDA recommends that adults consume less than 2.4 g of sodium per day. Flow many grams of sodium chloride can you consume and still be within the FDA guidelines Sodium chloride is 39% sodium by mass. ... 

SKILLBUILDER 6.8 Using Mass Percent Composition as a Conversion Factor... 

In the previous section, we learned how to calculate mass percent composition from experimental data and how to use mass percent composition as a conversion factor. We can also calculate the mass percent of any element in a compound from the chemical formula for the compound. Based on the chemical formula, the mass... 

Use the percent composition as a conversion factor between grams of titanium(IV) oxide and grams of titanium. 

The composition of very low density and low density Hpoproteins has been studied by a number of investigators. Data, summarized by Oncley (1963), are reported in Table 3. Values for the different components are in good agreement even though conversion factors were used for protein and phospholipid, cholesterol ester in weight percent was sometimes calculated from an assumed fatty acid... 

The mass percent composition of an element in a compound is a conversion factor between mass of the element and mass of the compound. For example, we saw that the mass percent composition of Cl in CCI2F2 is 58.64%. Since percent means per hundred, there are 58.64 g Cl per hundred grams CCI2F2, which can be expressed as the ratio ... 

STRATE6IZE Convert between mass of a constituent element and mass of a compound by using mass percent composition as a conversion factor. 

Using Mass Percent Composition as a Conversion Factor (3.9) Example 3.15 For Practice 3.15 For More Practice 3.15 Exercises 77, 78... 

Use percent composition and the relationship among density, volume, and mass as conversion factors in problem solving. 

Density and Percent Composition Their Use in Problem Solving—Mass and volume are extensive properties they depend on the amount of matter in a sample. Density, the ratio of the mass of a sample to its volume, is an intensive property, a property independent of the amount of matter sampled. Density is used as a conversion factor in a variety of calculations. 

Additional Conversion Factors in a Stoichiometric Calculation Volume, Density, and Percent Composition... 

The conversion factors in the calculation involve (1) the molar mass of Al, (2) stoichiometric coefficients from equation (4.2), (3) the molar mass of HCl, (4) the percent composition of the HCl solution, and (5) the density of the HCl solution. 

A standard practice gives the method of calculation of gas chromatographic response factors. The response factor is a constant of proportionality used for conversion of observed chromatographic response of a particular compoimd (e.g., peak area or peak height) to its mass or volume percent in composition. The standard shows how to obtain these response factors based on an example of a mixture of n-paraffins. 

---