Alkanes propane

Consider three compounds similar m size and shape the alkane propane the alkyl halide fluoroethane and the alcohol ethanol... 

These two reactions both begin with the same alkane (propane), and they both produce an alkyl radical and a hydrogen atom. 

The simplest of the saturated cyclic hydrocarbons, or cycloalkanes, is cyclopropane, C3Hg, the molecules of which are made up of three carbon atoms to each of which two hydrogen atoms are attached. Cyclopropane is somewhat more reactive than the corresponding open-chain alkane, propane, C3Hg. Other cycloalkanes make up a part of ordinary gasoline. 

The major hydrocarbon product is the parent alkane, propane, formed by loss of the carboxyl group. Smaller amounts of other fragments, such as propene, methane and hydrogen are also observed. These are most likely formed as a result of reactions of the propane radical for example propene can be formed by disproportionation of the propane radical ... 

The alkane propane has pATa 50, yet the presence of the double bond in propene means the methyl protons in this alkene have pATa 43 this value is similar to that of ethylene (pATa 44), where increased acidity was rationalized through sp hybridization effects. 1,3-Pentadiene is yet more acidic, having pATa 33 for the methyl protons. In each case, increased acidity in the unsaturated compounds may be ascribed to delocalization of charge in the conjugate base. Note that we use the term allyl for the propenyl group. 

Alkylcyclohexanes, cycloheptane, and cyclooctane were also transformed into the esters of the corresponding tertiary cyclohexanecarboxylic acids in the presence of the superelectrophile CBr4—2AlBr3 in good yields.314 315 Such organic superacids generated from polyhalomethanes with aluminum halides are capable of promoting the selective and effective carboxylation of linear alkanes (propane, butane) and adamantane as well.316... 

Catalytic hydrogenolysis of light alkanes (propane, butanes, pentanes) with the exception of ethane has been accomplished under very mild conditions over silica-supported hydride complexes.502 The hydrogenolysis proceeds over (=SiO)3 ZrH,503 (=SiO)3HfH,504 and (=SiO)3TiH505 by stepwise cleavage of carbon-carbon bonds by P-alkyl elimination from surface metal-alkyl intermediates. 

We have also examined olefin formation from higher alkanes. Propane and butane also produce up to 70% selectivity to olefins on Pt monolith ceramic foam monoliths at nearly 100% O2 conversion with alkane conversions of typically 80% at comparable flow rates and catalyst temperatures to those used for C2H6. However, olefins from these higher alkanes exhibit considerable cracking, with C2H4 the dominant product except at low temperatures and excess fuel. However, isobutane produces primarily isobutylene and C3H6 with litde C2H4. 

The first is the simplest, again with two methyl radicals, one on either side of the carbonyl group. Its molecular formula is CH CCXlHj. Its proper name is propanone propa- is used because of the relationship to the three-carbon alkane, propane, and -one is used because it is a ketone. It could logically be called dimethyl ketone, but it is universally known by its common name, acetone. Acetone is a colorless, volatile liquid with a sweet odor, has a flash... 

We can gain a sense of the relative importance of these intermolecuiar forces by considering three compounds similar in size and shape the alkane propane, the alkyl halide fluoroethane, and the alcohol ethanol. Both of the polar compounds, ethanol and fluoroethane, have higher boiling points than the nonpolar one, propane. We attribute this to a combination of dipole/induced-dipole and dipole-dipole attractive forces that are present in the liquid states of ethanol and fluoroethane, but absent in propane. 

Allyl anion is the conjugate base of propene thus, the extent to which electron delocalization stabilizes allyl anion can be assessed by comparing the p of propene to the alkane propane. The allylic hydrogens of propene are much more acidic than the hydrogens of propane, none of which are allylic. 

These reactions resemble each other in two respects they both begin with the same alkane (propane), and they both produce an alkyl radical and a hydrogen atom. They differ, however, in the amount of energy required and in the type of carbon radical produced. These two differences are related to each other. 

C/0P/5P have recently developed a process related to reforming to produce aro-matics-rich gasoline from aliphatic hydrocarbons. In this Cyclar process, the low-molecular weight alkanes, propane and butane, are used instead of naphtha. The flow diagram for the Cyclar process, which operates with zeolite catalysts, is shown in Figure 3.53. 

Typical VLE results for different C02-alkane systems are shown in Figures 5.93 and 5.94. While in Figure 5.93 only VLE data for four different C02-alkane (propane, butane, hexane, decane) are shown, for the system ethane -CO2 additionally the experimental and predicted azeotropic and critical data are shown. As can be seen, excellent results are obtained for all systems considered. This means that the group contribution concept can also be applied for the gases included in the PSRK matrix. 

Natural gas, often found associated with petroleum deposits, consists mainly of methane (about 80%) and ethane (5% to 10%), with lesser amounts of some higher alkanes. Propane is the major constituent of liquefied petroleum gas (LPG), a domestic fuel used mainly in rural areas and mobile homes. Butane is the gas of choice in some areas. Natural gas is becoming an energy source that can compete with and possibly surpass oil. In the United States, there are about a million miles of natural gas pipelines distributing this energy source to all parts of the country. Natural gas is also distributed worldwide via huge tankers. To conserve space, the gas is liquefied ( — 160°C), because 1 cubic meter (m ) of liquefied gas is equivalent to about 600 m of gas at atmospheric pressure. Large tankers can carry more than 100,000 m of liquefied gas. 

Shiju, N., Liang, X., Weimer, A., et al. (2008). The Role of Surface Basal Planes of Layered Mixed Metal Oxides in Selective Transformation of Lower Alkanes Propane Ammoxidation over Surface AB Planes of Mo-V-Te-Nb-O Ml Phase,/Am. Chem. Soc., 130, pp. 5850-5851. 

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