Calculations solution stoichiometry

Molarity M mol solute L solution in solution stoichiometry calculations... 

Calculating Parts per Million Sample Problem A p. 461 Preparing 1.000 L of a 0.5000 M Solution Skills Toolkit 1 p.463 Calculating Molarity Skills Toolkit 2 p.464 Sample Problem B p. 465 Solution Stoichiometry Sample Problem C p. 466... 

In chemical work, it is important to be able to calculate how much raw material is needed to prepare a certain quantity of products. It is also useful to know if a certain reaction method can prepare more product from a given quantity of material than another reaction method. Analyzing material means finding out how much of each element is present. To do the measurements, parts of the material are often converted to compounds that are easy to separate, and then those compounds are measured. All these measurements involve stoichiometry, tlie science of measuring how much of one thing can be produced from certain amounts of others. Calculations involving stoichiometry are also used in studying the gas laws, solution chemistry, equilibrium, and other topics. 

This is a very well-known reaction and has been used in sulfate analysis methods in the past. What is new and different here is that spectrophotometry is used to monitor the reaction as it progresses. In that way, one can tell when the reaction is complete (when all the sulfate is consumed), how much barium chloride solution has been added to that point, and then the amount of sulfate that was present calculated via stoichiometry. The graphical picture of the progress of the reaction suggested in the procedure is useful because you can visually observe the point at which the reaction is complete and then know the mL of the barium chloride solution used at that point. This is then the starting point for the stoichiometry calculation. 

Many environmental reactions and almost all biochemical reactions occur in solution, so an understanding of reactions in solution is extremely important in chemistry and related sciences. We ll discuss solution chemistry at many places in the text, but here we focus on solution stoichiometry. Only one aspect of the stoichiometry of dissolved substances is different from what we ve seen so far. We know the amounts of pure substances by converting their masses directly into moles. For dissolved substances, we must know the concentration—the number of moles present in a certain volume of solution—to find the volume that contains a given number of moles. Of the various ways to express concentration, the most important is molarity, so we discuss it here (and wait until Chapter 13 to discuss the other ways). Then, we see how to prepare a solution of a specific molarity and how to use solutions in stoichiometric calculations. 

Solution Stoichiometry Calculating Mass of Reactants and Products... 

Solution Stoichiometry Determining Limiting Reactants and Calculating Mass of Products... 

Solution Stoichiometry Calculating Volume in Neutralization Reactions... 

SOLUTION STOICHIOMETRY AND CHEMICAL ANALYSIS We see how the concepts of stoichiometry and concentration can be used to calculate amounts or concentrations of substances in solution through a common chemical practice called titration. 

Figure 4.5 I This flow diagram shows the important steps in a typical solution stoichiometry calculation.

Ch. 3 Stoichiometry Calculations with Chemical Formulas and Equations. Ch. 4 Aqueous Reactions and Solution Stoichiometry. 

Chapter 10 Reattions in Aqueous Solutions I Acids, Bases, and Salts) and Chapter 11 (Reactions in Aqueous Solutions II Calculations) include comprehensive discussions of acid-base and redox reactions in aqueous solutions and solution stoichiometry calculations for acid-base and redox reactions. 

In Chapter 3 we studied stoiehiometric calculations in terms of the mole method, which treats the eoeffieients in a balanced equation as the number of moles of reactants and products. In working with solutions of known molarity, we have to use the relationship MV = moles of solute. We will examine two types of common solution stoichiometry here gravimetric analysis and acid-base titration. 

To understand solution stoichiometry, you must first understand both fundamental stoichiometry concepts and solution concentrations. If you have difficulty solving solution stoichiometry problems, ask yourself if you thoroughly understand (a) writing chemical formulas from names, (b) calculating molar masses... 

Example 14.12 Solution Stoichiometry Calculating Equivalent Weight ... 

Example 14.14 Solution Stoichiometry Using Normality in Calculations... 

We complete the calculation of the mass of sodium acetate with some familiar ideas of solution stoichiometry. 

It was pointed out that a bimolecular reaction can be accelerated by a catalyst just from a concentration effect. As an illustrative calculation, assume that A and B react in the gas phase with 1 1 stoichiometry and according to a bimolecular rate law, with the second-order rate constant k equal to 10 1 mol" see" at 0°C. Now, assuming that an equimolar mixture of the gases is condensed to a liquid film on a catalyst surface and the rate constant in the condensed liquid solution is taken to be the same as for the gas phase reaction, calculate the ratio of half times for reaction in the gas phase and on the catalyst surface at 0°C. Assume further that the density of the liquid phase is 1000 times that of the gas phase. 

Single-Effect Evaporators The heat requirements of a singleeffect continuous evaporator can be calculated by the usual methods of stoichiometry. If enthalpy data or specific heat and heat-of-solution data are not available, the heat requirement can be estimated as the sum of the heat needed to raise the feed from feed to product temperature and the heat required to evaporate the water. The latent heat of water is taken at the vapor-head pressure instead of at the product temperature in order to compensate partiaUv for any heat of solution. If sufficient vapor-pressure data are available for the solution, methods are available to calculate the true latent heat from the slope of the Diihriugliue [Othmer, Ind. Eng. Chem., 32, 841 (1940)]. 

The efficiencies which may be obtained can consequently be calculated by simple stoichiometry from the equilibrium data. In the ease of countercurrent-packed columns, the solute can theoretically be completely extracted, but equilibrium is not always reached because of the poorer contact between the phases. The rate of solute transfer between phases governs the operation, and the analytical treatment of the performance of such equipment follows closely the methods employed for gas absorption. In the ease of two immiscible liquids, the equilibrium concentrations of a third component in each of the two phases are ordinarily related as follows ... 

Strategy Part (a) is essentially a stoichiometry problem of the type discussed in Chapter 4. For parts (b) and (c), start by calculating (1) the number of moles of OH added and then (2) the number of moles of H+ or OH- in excess. Finally, calculate (3) [H+] and pH. Remember to use the total volume of the solution at that point... 

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