Numbers to Remember

Gibbs energy decrease in the association reaction. The difference in AG° corresponding to a change of one unit in log or pfCd is -5.7 kj mol-1, a handy number to remember. 

This is a useful number to remember. It means that atmospheric pressure can support a column of water 34 ft (10.3 m) high. 

Chemists often say things like the pK of triethylamine is about 10. (It s actually 11.0 but 10 is a good number to remember for typical amines). This may surprise you as triethylamine has no acidic hydrogens. What they mean is of course this the pK of the conjugate acid of triethylamine is about 10. Another way to put this is to write the pX n of triethylamine is about 10. The subscript aH refers to the conjugate acid. 

This result is an important number to remember in many chemical reactor calculations—1 Ibmol of any (ideal) gas at 60°F and 1 atm occupies 379 ft. ... 

Yes, that s right It takes 9.807N (Newtons) to accelerate IKg (kilogram) of mass 1 m/sec —almost 10 times. This is a number to remember. See the note later in this section. 

Determining the exact rate for a given process can be a complicated accounting exercise, but there are often aspects of that rate that can be easily estimated. Furthermore, it is often helpful to adjust these estimates into numbers that are easy to work with. For instance, there are 60s in a minute and 60 min in an hour. So, there are 3600 s in an hour. If you have a rate of 35.22 per hour, round it up to 36 per hour, which equates to 0.01 per second—a penny per second. This is an easy number to remember and an easy number to work with. And while a penny per second may not seem like that critical of a number, the seconds mean pennies, pennies turn into dollars, and the dollars add up. 

The predictive power of the CPG neural network was tested with Icavc-one-out cross-validation. The overall percentage of correct classifications was low, with only 33% correct classifications, so it is clear that there are some major problems regarding the predictive power of this model. First of all one has to remember that the data set is extremely small with only 11 5 compounds, and has a extremely high number of classes with nine different MOAs into which compounds have to be classified. The second task is to compare the cross-validated classifications of each MOA with the impression we already had from looking at the output layers. 

Finally when equal locants are generated from two different numbering directions choose the direction that gives the lower number to the substituent that appears first m the name (Remember substituents are listed alphabetically)... 

With an atomic number of 28 nickel has the electron conflguration [Ar]4s 3c (ten valence electrons) The 18 electron rule is satisfied by adding to these ten the eight elec Irons from four carbon monoxide ligands A useful point to remember about the 18 electron rule when we discuss some reactions of transition metal complexes is that if the number is less than 18 the metal is considered coordinatively unsaturated and can accept additional ligands... 

It is important to remember that a theoretical plate is an artificial construct and that no such plates exist in a chromatographic column. In fact, the number of theoretical plates depends on both the properties of the column and the solute. As a result, the number of theoretical plates for a column is not fixed and may vary from solute to solute. 

We shall consider a number of different models in this volume. Before proceeding, it might be helpful to remember the status of the model in the methodology of science. Several things come to mind ... 

The convergence or divergence of an infinite series is unaffected by the removal of a finite number of finite terms. This is a trivial theorem but useful to remember, especially when using the comparison test to be described in the subsection Tests for Convergence and Divergence. ... 

As with metals, the number of different ceramics is vast. But there is no need to remember them all the generic ceramics listed below (and which you should remember) embody the important features others can be understood in terms of these. Although their properties differ widely, they all have one feature in common they are intrinsically brittle, and it is this that dictates the way in which they can be used. 

Now you can reconsider the material balance equations by adding those additional factors identified in the previous step. If necessary, estimates of unaccountable losses will have to be calculated. Note that, in the case of a relatively simple manufacturing plant, preparation of a preliminary material-balance system and its refinement (Steps 14 and 15) can usefully be combined. For more-complex P2 assessments, however, two separate steps are likely to be more appropriate. An important rule to remember is that the inputs should ideally equal the outputs - but in practice this will rarely be the case. Some judgment will be required to determine what level of accuracy is acceptable, and we should have an idea as to what the unlikely sources of errors are (e.g., evaporative losses from outside holding ponds may be a materials loss we cannot accurately account for). In the case of high concentrations of hazardous wastes, accurate measurements are needed to develop cost-effective waste-reduction options. It is possible that the material balance for a number of unit operations will need to be repeated. Again, continue to review, refine, and, where necessary, expand your database. The compilation of accurate and comprehensive data is essential for a successful P2 audit and subsequent waste-reduction action plan. Remember - you can t reduce what you don t know is therel... 

The names, number, and types of zones vary based on the aetivities at the worksite. The important thing to remember is that work zones are established to proteet the workers and the publie. Everyone on the site should understand the hazard(s) and eontrol(s) neeessary to support eaeh identified zone. Wind direetion was mentioned as an important eri-terion in ehoosing the support or elean zone. In most parts of the eountry, wind direetion ean be highly variable. If this is the ease at a given site, how should the support zone be handled The answer may vary based on the eonditions. 

Ideally, maintenance records should be organized by a classification method compatible with the CCPS Taxonomy in Appendix A and the equipment boundaries in Section 5.5, Generic Failure Rate Data Base. It is important to remember that the taxonomy presented was developed to group equipment into classes that are differentiated by their reliability rather than their design characteristics. Records maintained in this fashion allow the analyst to more easily determine the total pieces of equipment and number failures. 

Many of these have been demonstrated with a range of antibiotics and antibiotic precursors, although relatively few have been applied commercially. We have included a list of published examples in the form of an Appendix at the end of this chapter. We do not expect you to remember the details of this Appendix. It has been included as an potential for illustration of the potential to use enzymes to modify organic molecules like antibiotics. Usin9 It should be anticipated that, as enzyme technology develops and the search for new enzymes antibiotics continues, an increasing number of enzyme-based transformation will find commercial application. 

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