Energy forms

We summarize in Table 2.1 the physical dimensions of various energy forms. We emphasize that the list is not complete. In square brackets the physical dimension of the extensive variable has been given. The intensive variable has the energy-conjugated physical dimension. In the following sections, we discuss briefly some issues of the enagy forms detailed in Table 2.1. 

Energy name Energy form Physical dimension of intensive variable 

Gravitational energy (gravitational acceleration x mass height) g dmh J[kgm]-  

Material energy (chemical potential x mol number) jxdn J[mol]-  

Electrical energy (electric potential x charge) UedQ J[As]  

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Figure 4-10 [he Poteiitiiil Energy Form lor Ethylene. The midpoint of the range of (>) is (T and the end points -F180 . that is. [ a. Tt], The mid point and end points are identical by molecular symmetry. 

Figure 4-11 The Potential Energy Form for Ethane. The midpoint of the range of oj is m =0° and the end points are 180°. The end points and the minima are identical by molecular symmetry and correspond to the stable staggered form.

Figure 4-12 [ lie Potential Energy Form for -Butane. Hie energy is e.spressed relative to... 

The specific design most appropriate for biomass, waste combustion, and energy recovery depends on the kiads, amounts, and characteristics of the feed the ultimate energy form desired, eg, heat, steam, electric the relationship of the system to other units ia the plant, iadependent or iategrated whether recycling or co-combustion is practiced the disposal method for residues and environmental factors. 

Outlook. Since natural gas became a commodity of commerce and its potential as an energy form was recognized, its use on a worldwide basis has continued to increase. Adequate proven reserves have been developed and the necessary production and deflvery infrastmctures have been estabUshed... 

Obtaining explosives with the proper energy, form, and detonation velocity is difficult. 

J. K. Kowahek and D. R. Hay, S econd International Conference of the Center For High Energy Forming, Estes Park, Colo., June 23—27,1969. 

Fermentation is an anaerobic cataboHc process that uses organics as electron receptors. Since fermentation produces organic products that have lower free energy than their precursors, it is usefijl in remediation. The lowest free energy form of carbon produced is methane [74-82-8]. 

By substituting Equations 2.37 and 2.38 into Equation 2.35, maintaining the specific energy form, and regrouping, the following equation can be written ... 

The lowest energy form is acetaldehyde, about 27 millihartrees below the 0° form of vinyl alcohol. As was true for propene, the vinyl alcohol conformer where the C-C-O-H dihedral angle is 0° is the lower energy conformer. ... 

Examine both pyramidal and planar forms for each of the above molecules amine, phosphine and sulfoxide). Assume that the lower and higher-energy forms con-espond, respectively, to the preferred molecular structure and the transition state for configuration inversion. 

Display the electrostatic potential map for the lower-energy form of cyclooctatetraene. Where is the highest concentration of negative charge ... 

Is the second step of the overall reaction for R=Me (N-methylphthalimide + hydrazine —> phthalimide hydrazide + methylamine) exothermic or endothermic Will higher temperatures accelerate or inhibit the reaction Is the structure drawn above for phthalimide hydrazide its lowest-energy form or are either the imine or diimine tautomers preferred Compare energies for the hydrazide and imine and diimine tautomers. Examine the geometry of phthalimide hydrazide and any low energy tautomer, and draw the Lewis structure(s) that best describes it. Can your Lewis structures account for the energy differences Examine electrostatic potential maps for all three molecules. Which molecule(s) are stablized by favorable electrostatic interactions Which are destabilized Can this help explain the energy differences Elaborate. 

Examine pyrrole s highest-occupied molecular orbital (HOMO) to see if your can predict the most favorable protonation site. Which of the pyrrole s conjugate acids (N protonated, C2 proto noted, C3 proto noted pyrrole) is lowest in energy Examine electrostatic potential maps to see if the lowest-energy form is also that in which the positive charged is best delocalized. Rationalize your result using resonance arguments. What should be the favored substitution product ... 

To understand why a racemic product results from the reaction of T120 wjtl 1-butene, think about the reaction mechanism. 1-Butene is first protonaled tc yield an intermediate secondary (2°) carbocation. Since the trivalent carbon i sp2-hybridized and planar, the cation has no chirality centers, has a plane o symmetry, and is achiral. As a result, it can react with H20 equally well fron either the top or the bottom. Reaction from the top leads to (S)-2-butano through transition state 1 (TS 1) in Figure 9.15, and reaction from the bottorr leads to R product through TS 2. The two transition states are mirror images. The] therefore have identical energies, form at identical rates, and are equally likeb to occur. 

The enamine prepared from acetone and dimethylamine is shown here in its lowest-energy form. 

The various routes from agricultural production to fuel are shown in Figure 1. Products of agricultural production can be converted to a more available energy form as electricity and natural gas as shown in Figure 2. 

In some molecules, the twist conformation is actually preferred. In all cis-2,5-di-fert-butyl-l,4-cyclohexanediol, hydrogen bonding stabilizes the otherwise high-energy form and 1,3-dioxane 89 exists largely as the twist conformation shown. Of course, in certain bicyclic compounds, the six-membered ring is forced to maintain a boat or twist conformation, as in norbornane or twistane. 

Reactors Using Alternative Energy Forms for Green Synthetic Routes and New Functional Products... 

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