Conversion, factors affecting

Because the quantity is equivalent to 1, multiplying by the conversion factor affects only the units, not the actual quantity. To convert the other way, from centimeters to inches, we must—using units as a guide—use a different form of the conversion factor. If you accidentally use the same form, you will get the wrong result, indicated by erroneous units. For example, suppose that we want to convert 31.8 cm to inches ... 

The system of atomic units was developed to simplify mathematical equations by setting many fundamental constants equal to 1. This is a means for theorists to save on pencil lead and thus possible errors. It also reduces the amount of computer time necessary to perform chemical computations, which can be considerable. The third advantage is that any changes in the measured values of physical constants do not affect the theoretical results. Some theorists work entirely in atomic units, but many researchers convert the theoretical results into more familiar unit systems. Table 2.1 gives some conversion factors for atomic units. 

Conversion factors can be easily remembered if altered slightly, but not significantly enough to affect shortcut calculations. Here are some examples ... 

A threshold level of oxygen storage (via bulk PdO) is required to reach Ngh CO/NOx conversion levels in dynamometer sweep tests Pd loading, rather than dispersion or surface area, is the most impoirtant factor affecting oxygen uptakes. 

From Table 4, the reduction in ash content with increase in saturates content is clear, in spite of the higher ash level of the 22 % saturates HAO. The conversion peaks at 12 % saturates, which was unexpected and caimot be explained, except that many factors affect conversion and this could be the result of some other factor or a combination of factors. However, the reduction in conversion from 16 % saturates onwards is clear. 

In modern industrial ethyl alcohol plants, the compound is produced in two principal ways (I) by direct hydration of ethylene, or (2) by indirect hydration of ethylene. In the direct hydratiun process. H 0 is added to ethylene in the vapor phase in Lhe presence of a catalyst CH CH 4- H 0 CHiCHiOH. A supported acid catalyst usually is Used. Important factors affecting the conversion include temperature, pressure, the H 0/CH CH ratio, and the purity of (he ethylene, Further, some byproducts are formed by other reactions taking place, a primary side reaction being the dehydration of ethyl alcohol into diethyl ether 2C HjOH (C Hs)jO + HiO. To overcome these problems, a large... 

In this direct hydration process, a supported acid catalyst usually is used. Important factors affecting the conversion include temperature, pressure, the water/ethylene ratio, and the purity of the ethylene. Further, some by-products are formed by other reactions taking place, a primary side reaction being the dehydration of ethyl alcohol into diethyl ether ... 

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