Methane chemical properties

Chloroform, CHCla, is an example of a polar molecule. It has the same bond angles as methane, CH4, and carbon tetrachloride, CCLi- Carbon, with sp3 bonding, forms four tetrahedrally oriented bonds (as in Figure 16-11). However, the cancellation of the electric dipoles of the four C—Cl bonds in CCL does not occur when one of the chlorine atoms is replaced by a hydrogen atom. There is, then, a molecular dipole remaining. The effects of such electric dipoles are important to chemists because they affect chemical properties. We shall examine one of these, solvent action. 

Although the hybrid orbitals discussed in this section satisfactorily account for most of the physical and chemical properties of the molecules involved, it is necessary to point out that the sp orbitals, for example, stem from only one possible approximate solution of the Schrddinger equation. The i and the three p atomic orbitals can also be combined in many other equally valid ways. As we shall see on page 12, the four C—H bonds of methane do not always behave as if they are equivalent. 

One of the major organizing principles in organic chemistry is the presence of special arrangements of atoms. These so-called functional groups convey particular chemical properties. For example, a substance that contains an —OH group is called an alcohol. The systematic name of an alcohol is obtained by adding the suffix -ol to the name of the alkane with the same carbon framework. Thus, CH3 OH has the carbon framework of methane and is called methanol, whereas C2 H5 OH has the carbon framework of efhane and is called ethanol. 

Cheng W, Yagi K, Akiyama H, Nishimura S, Sudo S, Fumoto T, Hasegawa T. An empirical model of soil chemical properties that regulate methane production in Japanese rice soils. J. Environ. Qual. 2007 36 1920-1925. 

Watanabe A, Kimura M. Influence of chemical properties of soils on methane emission from rice paddies. Comm. Soil Sci. Plant Anal. 1999 30 2449-2463. 

Semiconductor electrodes seem to be attractive and promising materials for carbon dioxide reduction to highly reduced products such as methanol and methane, in contrast to many metal electrodes at which formic acid or CO is the major reduction product. This potential utility of semiconductor materials is due to their band structure (especially the conduction band level, where multielectron transfer may be achieved)76 and chemical properties (e.g., C02 is well known to adsorb onto metal oxides and/ or noble metal-doped metal oxides to become more active states77-81). Recently, several reports dealing with C02 reduction at n-type semiconductors in the dark have appeared, as described below. 

The ability of bimetallic systems to enhance various reactions, by increasing the activity, selectivity, or both, has produced a great deal of interest in understanding the different roles and relative importance of ensemble and electronic effects. Deposition of one metal onto the single-crystal face of another provides an advantage by which the electronic and chemical properties of a well-defined bimetallic surface can be correlated with the atomic structure.5 22 23 Besenbacher et al.24 used this method to study steam reforming (the reverse of the CO methanation process) on Ni(l 11) surfaces... 

The physical and chemical properties of hydrogen impose technical boundary conditions on standard methods of storing H2 in pure form, such as a pressurised gas or cryoliquid. Table 9.1 lists the physical properties of H2, in comparison with methane and n-heptane, which were chosen as representatives of natural gas and gasoline, respectively. 

Table 11.2. Safety-relevant physical and chemical properties of hydrogen, methane and n-heptane...

The 100 Most Important Chemical Compounds focuses on 100 compounds, but references several hundred compounds. Structures and formula for compounds other than the 100 are included in the entries and listed in the index. Repetition of information was kept to a minimum by including representative compounds or the simplest compound in a chemical family and highlighting chemical properties that distinguish chemical groups. For example, there are entries for methane, ethane, butane, and octane but other alkanes such as pentane, hexane, and heptane are not included. Most personal names in the book include years of birth and... 

Bloomer, O.T., Garni, D.C., and Parent, J.D. Physical-Chemical Properties of Methane-Ethane Mixtures, Research Bulletin, Institute of Gas Technology, Chicago (1953) 22. 

The chemical properties of lithium hydride, methane, and hydrogen fluoride are in accord with the above formulations. Thus, when the bond to the hydrogen is broken, we might expect it to break in the senseLi Hefor... 

Flames formed from air combined with the lighter hydrocarbons, such as methane, propane, butane, or natural gas, behave in a very similar fashion with similar temperatures, similar chemical properties, etc. 

The fascination with the abundances of the atomic nuclei is that they inform of ancient events. The events that are recorded in their populations depend upon the material sample in question. In the crust of the Earth, they record its geologic evolution. Silicon in that crust is much more abundant than iron, for example, because the Earth s crust is sandy, whereas its iron sank to the Earth s core during its early molten state. In the Earth s oceans the elemental abundances reflect their solubilities in water. In the Earth s atmosphere, their numbers reflect their volatilities. And so it goes. Such abundance-sets reflect and record the geophysical history of the Earth and the chemical properties of the chemical elements. Atmospheric carbon dioxide (C02) and methane (CH4) record an extra wrinkle, the impact of human beings on the Earth s atmosphere. 

Q O All hydrocarbons have the chemical property of combustion in the presence of oxygen. How do the complete combustion reactions of methane, ethane, and propane differ How are they similar ... 

Oxidation kinetics, 292-293 Reduction kinetics, 288 Removal from solution, 443-445 pe-pH diagram, 256,441 Manganese carbonate, 59,433 Manganese oxides, 131 Methane, 257-258, 324 Mica, 102-108 Layer charge, 113 Structure, 115 Molecular Weight, 13,14 Mole fraction, 202 Equivalent fraction, 202 Montmorillonite., 102,104, 109, 123 C-axis spacings, 171 Layer charge, 120 Structure, 171 Composition, 104 Physical properties, 123-124 Chemical properties, 123-124 Muscovite, 104, 123 Structure, 108 Composition, 104... 

What happens to an organic compound when it is dumped into the environment Clearly, the answer depends on the physical and chemical properties of the compound. For example, a big spill of methane will not cause a water pollution problem, but a major release of DDT could cause a big problem for biota. This chapter will provide a few tools for looking quantitatively at these issues. Of necessity, we will be brief, but for a more complete coverage, the reader is referred to the massive book by Schwarzenbach et al.1... 

This constitution has been proved by various methods by X-ray analysis of di-(9-phenanthridyl)methanes24,26 and 8-bromodi-(2-quinolyl)methane,15 by the magnitude of the oscillator strength of quinolylmethanes which are entirely in the colored form,25 by chemical properties (neither iV-acetyl nor iV-nitroso derivatives could be prepared1) and by infrared data which failed to indicate a normal... 

Constitution.—The composition of naphthalene is represented by the formula CioHg. What is its constitution In the first place it is a hydrocarbon similar in its chemical properties to benzene and not to methane. It readily forms nitro and sulphonic acid derivatives and its hydroxyl derivatives are analogom to phenols, not to alcohols. It also yields hydrogen and halogen addition products like benzene. The true constitution of the compound has been established by reactions both of decomposition and of synthesis. 

The nonreactivity of O2CIF3 with hydrogen and methane parallels the chemical properties of ozone. Pure (100%) ozone can be mixed at —78° C. and even at room temperature with hydrogen and methane without reaction (7, 8). (The mixture 1.5 CH4 + 2 O3, at 804 mm. of Hg, showed at +21° C. a pressure increase of 26 mm. of Hg on standing for 1.0 hour.)... 

In its chemical properties as in its physical properties, methane sets the pattern for the alkane family (Sec. 3.18). Typically, it reacts only with highly reactive substances—or under very vigorous conditions, which, as we shall see, amounts to the same thing. At this point we shall take up only its oxidation by oxygen, by halogens, and even by water. 

---