Mole balances summary

Table 3.5.3 Summary of Mole Balances - Methanol-Synthesis Process... 

However this "definition" is wrong It is simply a mole balance that is only valid for a constant volume batch system. Equation (1-1) will not apply to any continuous-flow reactor operated at steady state, such as the tank tCSTR) reactor where the concentration does not vary from day to day (i.c.. the concentration is not a function of time). For amplification on this point, see the section "Is Sodium Hydroxide Reacting " in the Summary Notes for Chapter 1 on the CD-ROM or on the web. 

The startup of a fixed volume CSTR under isothermal conditions is rare, bu does occur occasionally. We can, however, carry out an analysis to estimate time necessary to reach steady-state operation. For the case when the reacto Summary Motes well mixed and as a result there are no spatial variations in Tai begin w the general mole balance equation applied to Figure 4> 14(a) ... 

Summary of mole balances for several ideal reactors.. . ... 

A summary of the heat and mole balance equations is given in Table El 3-1.1. 

This is an electrochemical stoichiometry problem, in which an amount of a chemical substance is consumed as electrical current flows. We use the seven-step strategy in summary form. The question asks how long the battery can continue to supply current. Current flows as long as there is lead(IV) oxide present to accept electrons, and the batteiy dies when all the lead(IV) oxide is consumed. We need to have a balanced half-reaction to provide the stoichiometric relationship between moles of electrons and moles of Pb02. 

The MAM described here is a generalization of the model previously published (10). Hence, only a summary of the derivation will be given here. Details can be found elsewhere (17). The basic equations are the surfactant and counterion material balances and the minimization of the Gibbs free energy of the system with respect to the micelle concentration c , and mole fraction x (11). Equation 4 from Ref. (11) has been changed to... 

FIGURE 3.2 A summary of conversions between moles and grams for a chemical reaction. The numbers of moles tell how many molecules of each reactant are needed, as given by the coefficients of the balanced equation the numbers of grams tell what mass of each reactant is needed. 

Changing the recovery of ethanol from 99-99.99%m produces only minor increases in the heat loads. A summary of the column material balance for one mole of feed is shown in Table V when the solvent-feed ratio is 3.5 mole basis. This calculation was made for a recovery of 99.99% ra ethanol using 46 equilibrium trays with the solvent on 43 and the feed on 22. The reflux-feed ratio was 1.5537 mole basis. The corresponding data for temperature, composition, and volatility profiles are summarized in Table VI. 

We first write the balanced equation for the acid-base reaction and then construct the reaction summary that shows the amounts (moles) of HCl and NaOH. We determine the amount of salt formed from the reaction summary. The final (total) volume is the sum of the volumes mixed. Then we calculate the molarity of the salt. 

We express all concentrations in moles per liter. The mole ratio from the balanced chemical equation allows us to find the changes in concentrations of the other substances in the reaction. We use the reaction summary to find the equihbrium concentrations to use in the... 

General Steps Use a unit analysis format. Set it up around a mole-to-mole conversion in which the coefficients from a balanced equation are used to generate a mole ratio. (See Figure 10.1 for a summary.) The general steps are... 

Check The Change row of the summary table shows that the mole ratio of reactants consumed and product formed, 2 6 4, conforms to the coefficients in the balanced equation, 1 3 2. Because H2 is the limiting reactant, it is completely consumed in the reaction, leaving 0 mol at the end. Because 6.0 mol H2 has two significant figures, our answer has two significant figures. 

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