Notes on the following

The activity of a catalyst can often be increased by the addition of a small quantity of a second material. This second substance is either not a catalyst itself for the reaction or it may be a feeble catalyst. 

A substance which, though itself not a catalyst, promotes the activity of a catalyst is called a promoter or an activator. 

The theory of promotion of a catalyst is not clearly understood. It may probably be due to  

Very often a heterogeneous catalyst is rendered ineffective by the presence of small amounts of impurities in the reactants. 

A substance which destroys the activity of the catalyst to accelerate a reaction, is called a catalytic poison and the process is called catalytic poisoning. 

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Make brief explanatory notes on the following concepts. Source material may be found in both Chapters 1 and 3 (a) the template effect (b) the chelate and macrocyclic effects (c) the high dilution technique in macrocyclic synthesis and (d) preorganisation and complementarity. 

Problem 4 Define and discuss or write short notes on the following ... 

Write a short note on the following oral hypoglycemic agents ... 

Write short notes on the following methods of synthesising chiral molecules a using a chiral auxiliary... 

Notes on the operation of a precision fractionating column. The following notes on the technique of conducting a fractionation under diminished pressure may be of value to the student their adaptation to fractionation at atmospheric pressure should not present any difficulty. 

Note on the laboratory preparation of monoethylaniline. Although the laboratory preparation of monomethyl- or monoethyl-aniline is hardly worth whUe, the following experimental details may be useful to those who wish to prepare pure monoethylaniline directly from amline. In a flask, fitted with a double surface reflux condenser, place 50 g. (49 ml.) of aniline and 65 g. of ethyl bromide, and boU gently for 2 hours or until the mixture has almost entirely sohdified. Dissolve it in water and boil off the small quantity of unreacted ethyl bromide. Render the mixture alkaUne with concentrated sodium hydroxide solution, extract the precipitated bases with three 50 ml. portions of ether, and distil off the ether. The residual oil contains anihne, mono- and di-ethylaniline. Dissolve it in excess of dilute hydrochloric acid (say, 100 ml. of concentrated acid and 400 ml. of water), cool in ice, and add with stirring a solution of 37 g. of sodium nitrite in 100 ml. of water do not allow the temperature to rise above 10°. Tnis leads to the formation of a solution of phenyl diazonium chloride, of N-nitrosoethylaniline and of p-nitrosodiethylaniline. The nitrosoethylaniline separates as a dark coloured oil. Extract the oil with ether, distil off the ether, and reduce the nitrosoamine with tin and hydrochloric acid (see above). The yield of ethylaniline is 20 g. 

In Sec. 1.4 we discussed the classification of polymers into the categories of addition or condensation. At that time we noted that these classifications could be based on the following ... 

Nonemptiness of the set depends on the values of the function (p on T. For further consideration we should note that the following inequality holds in... 

Include a note on the reason why in eveiy instruc tion, code, and standard, and accounts of accidents which would not have occurred if the instruction, code, or standard had been followed. 

Several factors are important in the performance of a generator, and not the service conditions alone, as discussed for motors, in Section 1.6. In addition to service conditions, the operating power factor plays a significant role in the selection of a DG set, as noted above. The following p.f. conditions may occur in practice, depending upon the type of loads connected on the system. Refer to Figure 16.8. 

The chemistry of amines ts dominated by the lone pair of electrons on nitrogen, which makes amines both basic and nucleophilic. They react with acids to form acid-base salts, and they react with electrophiles in many of the polar reactions seen in past chapters. Note in the following electrostatic potential map of trimethylamine how the negative (red) region corresponds to the lone-pair of electrons on nitrogen. 

Although the results eu e equal as far as utility is concerned, we shedl continue to use our symbolism, for reasons which will become clearer later on. The following Table is a comparison of defect symbolism, as used by prior Authors. Note that our symbolism most resembles that of Kroeger, but not in aU aspects. These prior authors also considered other intrinsic defects that we have not touched, namely interstices and the so-called "anti-structure" occupation. 

A suitable apparatus is shown on the following following page cis 7.5.3. Note that only a means of holding one end of the sample bar is needed while the sample is being heated. Most materials expand only about a small fraction of their actual dimensions. Because they expand less than a micrometer, i.e.- one millionth of a meter, with a one-degree increase in temperature, measurements... 

Notes on the preparation of secondary alkylarylamines. The preparation of -propyl-, ijopropyl- and -butyl-anilines can be conveniently carried out by heating the alkyl bromide with an excess (2-5-4mols) of aniline for 6-12 hours. The tendency for the alkyl halide to yield the corresponding tertiary amine is thus repressed and the product consists almost entirely of the secondary amine and the excess of primary amine combined with the hydrogen bromide liberated in the reaction. The separation of the primary and secondary amines is easily accomplished by the addition of an excess of per cent, zinc chloride solution aniline and its homologues form sparingly soluble additive compounds of the type B ZnCl whereas the alkylanilines do not react with sine chloride in the presence of water. The excess of primary amine can be readily recovered by decomposing the zincichloride with sodium hydroxide solution followed by steam distillation or solvent extraction. The yield of secondary amine is about 70 per cent, of the theoretical. 

In addition to these generalized approaches of genomics and proteomics, it has been predicted that pharmacogenomics may revolutionize drug discovery and treatment for the individual, based on the following (and with some of the consequences noted) [12] ... 

Below and on the following pages are tables that are typical of the type you might be asked to read in a textbook or on the job. Note their simplicity and economy. 

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