Dilution formula

Suhstance Ddution Formula Heat, kg-cal/ g-mole Substance Dilution Formula Heat, kg-cal/ g-mole... 

The last definition has widespread use in the volumetric analysis of solutions. If a fixed amount of reagent is present in a solution, it can be diluted to any desired normality by application of the general dilution formula V,N, = V N. Here, subscripts 1 and 2 refer to the initial solution and the final (diluted) solution, respectively V denotes the solution volume (in milliliters) and N the solution normality. The product VjN, expresses the amount of the reagent in gram-milliequivalents present in a volume V, ml of a solution of normality N,. Numerically, it represents the volume of a one normal (IN) solution chemically equivalent to the original solution of volume V, and of normality N,. The same equation V N, = V N is also applicable in a different context, in problems involving acid-base neutralization, oxidation-reduction, precipitation, or other types of titration reactions. The justification for this formula relies on the fact that substances always react in titrations, in chemically equivalent amounts. 

Whenever flowrates of the olfactometer and human respiration levels do not match, the dilution formula should be extended to ... 

Solution The dilution formula handles this problem directly ... 

Substance Dilution" Formula Heat, kcahmol Substance Dilution" Formula Heat, kcahmol... 

An 8-month-old child presents with exhaustion, irritability, and malnutrition. The family history reveals poverty and inadequate nutrition in all members. The 8-month-old was fed diluted formula, and the tentative diagnosis of marasmus was made. 

Note that 2.5 is not the number of cubic centimeters of water to be added, but the final volume of the solution after water has been added to 1 cm of the original solution. The dilution formula always gives answers in terms of the total volume of solution. If we can assume that there is no volume shrinkage or expansion on dilution, the amount of water to be added in this problem is 1.5 cm per cubic centimeter of original solution. Unless this assumption is made, the answers in the subsequent problems will be left in terms of the total volumes of the solutions. (The assumption of volume additivity is usually good for dilute solutions, e.g., <0.1 M). 

Substance Dilution Formula Heat, kcal/mol Substance Dilution Formula Heat, kcal/mol... 

Pool size estimated by isotope dilution formula, using the specific activity of the duodenal sample obtained 3 hr after injection of the labeled bile salt (3). 

The other systems used in the study were somewhat more variable in composition. Some were standard examples of common dairy products (30) full cream and reconstructed cream (made by mixing cream with skim milk). They too gave much more consistent results when analyzed using the concentrated formula than were obtained with the dilute formula [Eq (2)]. It should also be noted that the zeta potential and size data obtained for the concentrated systems (cream and reconstituted cream) before and after dilution are reasonably consistent (comparing Tables 1 and 2). Both show almost the same size, and the zeta potentials differ by only 5 to 6 mV, which suggests that the dilution procedure used in preparing the data for Table 1 is more satisfactory than the alternatives but that one should still favor the results obtained on systems which have not been diluted at all. 

This dilution formula can be used when there is only one solute present If a reaction is taking place, the problem must be approached as a stoichiometry problem, which we will take up in Chapter 4. 

This is the type of problem that smdents get wrong if they use the dilution formula (Eq. 3.3) by mistake. The dilution formula does not include the mole ratio from a balanced chemical equation, and in this case, the 2 1 ratio would result in an error of a factor of 2 if you used Eq. 3.3. 

To use the dilution formula, we need to express volume in liters. Table 1-4 told us that there are 1 000 L in 1 cubic meter. Therefore the volume of the reservoir in liters is... 

To find the concentration of the dilute solution, use the dilution formula 1-5 ... 

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