Solution Calculations

We discuss solutions further in the chapter on solutions and colligative properties, but solution stoichiometry is so common on the AP exam that we will discuss it here briefly also. Solutions are homogeneous mixtures composed of a solute (substance present in smaller amount) and a solvent (substance present in larger amount). If sodium chloride is dissolved in water, the NaCl is the solute and the water the solvent. 

One important aspect of solutions is their concentration, the amount of solute dissolved in the solvent. In the chapter on solutions and colligative properties we will cover several concentration units, but for the purpose of stoichiometry, the only concentration unit we will use at this time is molarity. Molarity (M) is defined as the moles of solute per liter of solution  

Let s start with a simple example of calculating molarity. A solution of NaCl contains 39.12 g of this compound in 100.0 mL of solution. Calculate the molarity of NaCl. 

Knowing the volume of the solution and the molarity allows you to calculate the moles or grams of solute present. 

let s see how we can use molarity to calculate moles. How many moles of ammonium ions are in 0.100 L of a 0.20 M ammonium sulfate solution  

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I. 000 X 10- 1.000 X 10-k 1.000 X 10-k and 1.000 X 10- M from a 0.1000 M stock solution. Calculate the uncertainty for each solution using a propagation of uncertainty, and compare to the uncertainty if each solution was prepared by a single dilution of the stock solution. Tolerances for different types of volumetric glassware and digital pipets are found in Tables 4.2 and 4.4. Assume that the uncertainty in the molarity of the stock solution is 0.0002. 

A. M. Walsh, R. D. Coalson. Lattice field theory for spherical macroions in solution Calculation of equilibrium pair correlation function. J Chem Phys 700 1559-1566, 1994. 

Solution Calculate the R factor and determine the tracer requirements from Table 10-46. 

Given the pH and original concentration of a weak acid solution, calculate Ka. 

Phenol, once known as carbolic acid, HC6H50, is a weak add. It was one of the first antiseptics used by lister. Its K, is 1.1 X 10-1C. A solution of phenol is prepared by dissolving 14.5 g of phenol in enough water to make 892 mL of solution. For this solution, calculate... 

SOLVENT EFFECTS WITH QUANTUM MECHANICAL SOLUTE CALCULATIONS... 

To illustrate the application of corresponding-states theory to polymer solution calculations, we consider two cases of sol-vent/polymer vapor-liquid equilibria. The first case we consider is that of the chloroform/polystyrene solution. The second is that of benzene/polyethylene oxide. 

C03-0121. For each of the following salt solutions, calculate the amounts in moles and the numbers of each type of... 

C03-0122. For each of the following salt solutions, calculate the amounts in moles and the numbers of each type of Ion (a) 2.87 L of 0.0550 M lithium carbonate (b) 325 mL of a solution that contains 1.02 X lO formula units of sodium hydrogen sulfate and (c) 2.55 mL of a solution that contains 263 mg/L of sodium oxalate. 

The small amounts of gold contained in low-grade ores can be extracted using a combination of oxidation and complexation. Gold is oxidized to Au, which forms a very strong complex with cyanide anions Au ((2 q) + l CN(a q) [Au (CN)2] aq) K -lx 10 Suppose that a sample of ore containing 2.5 X 10 mol of gold is extracted with 1.0 L of 4.0 X 10 M aqueous KCN solution. Calculate the concentrations of the three species involved in the complexation equilibrium. 

Solution Calculate the liquid composition at the rectifying pinch using Equation 9.57. But first, the root of the second Underwood Equation associated with the heavy key component must be calculated. From Table 9.1, this lies in the range ... 

Fig. 39. Crossover from 0- to good solvent conditions in dilute solutions. Calculated characteristic frequencies, normalized to 0-conditions, as dependent on reduced temperature for two different chain lengths N at various values of (QS). To the right of each curve the increase in Qred (q,x) between t = 0 and t = 0.9 is given...

Figure 5 shows pn distributions for spherical observation volumes calculated from computer simulations of SPC water. For the range of solute sizes studied, the In pn values are found to be closely parabolic in n. This result would be predicted from the flat default model, as shown in Figure 5 with the corresponding results. The corresponding excess chemical potentials of hydration of those solutes, calculated using Eq. (7), are shown in Figure 6. As expected, /x x increases with increasing cavity radius. The agreement between IT predictions and computer simulation results is excellent over the entire range d < 0.36 nm that is accessible to direct determinations of po from simulation.

Rate Constants and Activation Energies of Reaction RH + 03 —> R + HO3 in the Hydrocarbon Solution Calculated by the IPM Method (see Chapter 4, [133])... 

Enthalpies, Activation Energies, and Rate Constants of Reactions of p-Benzoquinone with Phenols and Amines InH + Q > In + HQ in Hydrocarbon Solutions Calculated by IPM Method for Equations See Chapter 6 and for the Values of a, bre, and A, See Table 18.9... 

Fig. 14.8. Concentrations (mmolal) of sites on a hydrous ferric oxide surface exposed at 25 °C to a 0.1 molal NaCl solution, calculated using a sliding pH path.

Figure 11A shows a theoretical example of a titration curve A + B = AB, where the signal is proportional to the amount of complex. The solid lines represent conditions where Bmax is equal to KD. Here for both presentations of signal vs either [Atotal] (total concentration of A added to the preparation) or [Afree] (concentration of non-complexed A in the solution, calculated as [Atotal] - ([AB]) the plot is curved and allows discrimination between free and complexed binding partners. If [Bmax] is substantially higher than KD the issue of active site... 

For each solution, calculate the number of moles of acid added. The moles of acid was constant for each solution,... 

For each solution, calculate the number of moles of OH added. 

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