Getting the answer

And now, for the trick. If you were able to see all of that, great But if you had trouble seeing the molecules in 3D, there is a simple trick that will help you get the answer every time. To understand how the trick works, you need to realize that if you redraw the molecule so that any two of the four groups are switched, then you have switched the configuration (R turns into S, and S turns into R) ... 

However, MATLAB allows us to get the answer with very little work—something that is very useful when we deal with more complex systems. Consider a numerical problem with values of the process gain Kp = 1, and process time constants X = 2 and x2 = 4 such that the closed-loop equation is... 

Again for illustration purpose, we supposedly have chosen Kc such that KcKvKpKm = 5, and xp is the mixing process time constant. Find, without trial-and-error and without further approximation, the maximum distance L that the photodetector can be placed downstream such that the system remains stable. (There are two ways to get the answer. The idea of using magnitude and phase... 

We used the data in Table 14-2. We doubled the species in the first chemical equation, but did not change the potential. We reversed the second equation, and changed the sign of the potential. We then added both the chemical equations and the potentials to get the answer. 

Try taking this short mathematics self-test. If you understand these math problems and get the answers correct, you re ready to go on. If you miss problems in this area, you need to back up and review those operations with which you are uncomfortable. 

At this point you can rule out choices B, C, and D because they do not make sense. If you have forgotten how to do the problem mathematically, you should guess now you have a 50% chance of getting the answer right. 

However, remember that the question calls for the answer per mole of C2H6. Thus, because the balanced equation is written for 2 moles of C2HS, simply divide -696.0 by 2 and you get the answer -348.0. 

This method allows us to get the answer without calculating an intermediate value. It also avoids the possibility of too much rounding, which is always a concern in multistep problems. 

You may find some discrepancies while trying to interpret the values of amines on the basis of +1 or -1 effect of the substituents present in amines. Besides inductive effect, there are other effects like solvation effect, sterlc hlnderance, etc., which affect the basic strength of amines. Just ponder over. You may get the answer In the following paragraphs. 

This work has also taught us—and this is a promising new field of applications— how to get a fresh insight into individual bond dissociation energies and their dependence on whatever events modify the electronic structures of the concerned reaction sites. This area only awaits the inventiveness of our community, a community that never lacks questions and ideas to get the answers. So much for the future. 

Well, you can, but you will need one more piece of evidence before you do the calculation. Fortunately the laboratory is not closed and they do have the ability to measure plasma phenytoin. It takes about 30 minutes to get the answer from the lab -6 mg/1. Remember the therapeutic concentration that was needed to give the patient a therapeutic level was 15 mg/1. 

Pay attention to little details like final units when you re answering chemistry questions. They re easy to overlook, but they make all the difference between getting the answer right and getting it wrong. 

The nice thing about percents is that their values are easy to relate to. If you re 75 percent finished with a project, then you know that you re well on your way. You compare the percentage to 100 — a nice, round number — and have a good idea of what the value is in the comparison. To be more exact with an answer, though, you need to convert percentages to decimals and create a more exact value to use in computations. Using the decimal equivalents, you can solve for the percent of a value and get the answer in items, and you can also solve for how many items are needed to reach a certain percent. 

Even though cross-multiplying is a great tool to use when solving proportions, you can often take an easier route Flip the fractions (set the reciprocals equal to one another) and then multiply each side by the same number to solve the equation. For example, in the following equation, I flip the proportion and then just have to multiply each side by the number under the x, reduce, and get the answer. 

When dividing fractions, simply multiply the dividend by the divisor s reciprocal to get the answer. For example ... 

There is yet more to justify our need of a handy shortcut fractionation method. These wonderful commercial software programs previously discussed may not be available. Remember that most companies limit who can run these programs, and you may be required to wait a long time to get your needs met. I again rest my case here that you will have at your fingertips the shortcut method in this book. It is also a computer program. Set up for your particular problem on the shortcut method proposed herein, then run many different conditions, and you will establish expected answers before you can get the answers on the more expensive commercial programs. 

I left the defaulted name, Command 1, on the Properties menu since this is indeed the program s chief button that must be clicked each time the program is run. Whenever you make changes to the input files, Table 1 or 2, or make PI or T1 text box changes, this Run Prog, command button must be clicked to get the answers per changes. 

There may be other solutions of the problem at hand. The system thus asks whether we are satisfied with the solution just given or whether it should try to find alternate solutions. In some implementations the system poses the respective question explicitly, awaiting a specified response (generally yes or no). Other systems just wait for the user to act. The convention in these systems is often that a carriage return signals accepting the solution, where as input of a indicates that alternate solutions are to be found. In the present case, there are no other solutions. Thus, if we ask for more we get the answer no. Another interesting question may be... 

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