For methyl chloride

A diagrammatic illustration of the effect of an isotope pattern on a mass spectrum. The two naturally occurring isotopes of chlorine combine with a methyl group to give methyl chloride. Statistically, because their abundance ratio is 3 1, three Cl isotope atoms combine for each Cl atom. Thus, the ratio of the molecular ion peaks at m/z 50, 52 found for methyl chloride in its mass spectrum will also be in the ratio of 3 1. If nothing had been known about the structure of this compound, the appearance in its mass spectrum of two peaks at m/z 50, 52 (two mass units apart) in a ratio of 3 1 would immediately identify the compound as containing chlorine. 

Production and sales data for methyl chloride, as reported by the U.S. International Trade Commission for the years 1945 to 1989, are given in Table 3. Production grew tremendously in the 1960s and again in the late 1980s. Methanol hydrochlorination was used to produce about 64% of the methyl chloride in 1969 and about 98% by 1974. The principal U.S. producers and their capacities are shown in Table 4 (54). These capacities do not include the 100 + million kg per year used by The Dow Chemical Company, Occidental, and Vulcan to captively produce other chloromethanes. 

Ref 54. Vulcan has recently bought out Vista. The historical growth rate (1979—1988) for methyl chloride is 1.7% per year. The projected growth rate through 1993 is projected demand in 1993 is 264,000 t. Methyl chloride is used primarily in the manufacture of siHcones (Table 5). Table 5. Uses of Methyl Chloride 1 to 2% per year. The... 

The most widely used method of analysis for methyl chloride is gas chromatography. A capillary column medium that does a very good job in separating most chlorinated hydrocarbons is methyl siUcone or methyl (5% phenyl) siUcone. The detector of choice is a flame ionisation detector. Typical molar response factors for the chlorinated methanes are methyl chloride, 2.05 methylene chloride, 2.2 chloroform, 2.8 carbon tetrachloride, 3.1, where methane is defined as having a molar response factor of 2.00. Most two-carbon chlorinated hydrocarbons have a molar response factor of about 1.0 on the same basis. 

Display the dipole moment for methyl chloride. Is chlori at the -b or - end ... 

Methylene Chloride and Chloroform.—Curves for CH3C1, CH2C12 and CHC13 (Table IX) are shown in Fig. 7. The maximum for methyl chloride lies at 1.80 A. we do not consider this value... 

Fig. 7.—Radial distribution curves for methyl chloride, methylene chloride and chloroform.

Further degradation to formate may involve the tetrahydrofolate (THE) or tetrahydro-methanopterin pathways (Marx et al. 2003) that are comparable to those used for methyl chloride and methyl bromide, which are discussed in Part 3 of this chapter. 

Table 3. Measured (Black and Law 2001) and ab initio vibrational frequencies for methyl chloride, C CX.Ab initio frequencies are calculated with GAMESS, using the Hartree-Fock method and 6-31G(d) basis set. The ratio of each measured and model frequency is also shown.

The 2003 ACGIH threshold limit valuetime-weighted average (TLV-TWA) for methyl chloride is 50ppm (103mg/m ) with a shortterm excursion limit (STEL)/ceiling of 100 ppm (207mg/m ) and a notation for skin absorption. 

As seen from the data in Table 7-4 (abstracted from frequencies provided in Appendix A7) symmetric methyl group CH stretching frequencies change with substitution. The smallest value is for methylamine (chosen as the reference compound) and the largest is for methyl chloride. (Ethane has been excluded from this comparison as the symmetric stretch here involves all six hydrogens.)... 

Roush, G. J. Coyne, L. S. Charcoal Sampling Method for Methyl Chloride, a Gas with Low Charcoal Affinity Am. Ind. Hyg. Conference Paper 340, 1980. 

Production capacity for methyl chloride in the United States was reported to be... 

The use pattern for methyl chloride in the United States in 1992 and 1995 was (%) methyl chlorosilanes used as intermediates for silicones, 80 methyl cellulose manufacture, 6 quaternary ammonium compounds, 5 agricultural chemicals, 5 butyl rubber production, 2 and miscellaneous, 2 (Anon., 1992, 1995). 

No international guideline for methyl chloride in drinking-water has been established (WHO, 1993). 

Their toxicity hazard are given. by Sax (Ref 2). Balis et al (Ref 1) have detd flammability data and established the critical oxygen content i.e, the O content below which flame propagation is not possible in a gaseous atm, no matter what its chlorosilane content. A summary of these data establishing this critical O content for 4 chlorosilanes for methyl chloride (chloromethane, qv) by means of a modified BurMines - App is given above ... 

Methyl chloride is the only chlorinated methane with good growth. The principal use for methyl chloride is in the manufacture of chlorosilanes (89%) for the silicone industry. Other smaller uses are for methyl cellulose ether, quaternary ammonium compounds, herbicides, and butyl rubber. 

If attention at first is confined to the production of methyl silicone from the previously accepted raw materials, the chemical processes must include reduction of silica to silicon, preparation of the methyl chloride from methane or methanol, reaction of the methyl chloride with silicon, and hydrolysis of the methylchlorosilanes. If the same conventions are used as in the discussion of the,Grignard method, and the methanol process for methyl chloride is elected, the steps are ... 

A picture of the electron distribution in the a orbitals between carbon and chlorine is revealed in the wire-mesh diagrams for methyl chloride in Fig. 1.47, which shows one contour of the major orbital crccl contributing to C—Cl bonding together with the LUMO, this book. Comparing these with the schematic version in Fig. 1.46, we can see how the back lobe on carbon in hydrogen atoms, and that the front lobe in cr ccl wraps back a little behind the carbon atom to include some overlap to the s orbitals of the hydrogen atoms. 

Fig. 1.47 The major C—Cl bonding orbital and the LUMO for methyl chloride...

For discussion of intramolecular forces it is essential to remove from consideration effects due to intermolecular forces, that is, to have heats of formation referring to the ideal gas state. In general the correction of heats of formation of real gases at 1 atmosphere pressure to the ideal gas state is very small compared with the accuracy to which heats of formation are known for example, approximately 0-002 kcal mole for methane and 0-02 kcal for methyl chloride. This means that for all purposes connected with bond energies, a knowledge of the heat of formation of the real gas is adequate. Thus for substances whose heat of formation is known directly for the liquid or solid, a knowledge of the heat of vaporization at the appropriate temperature is required. Strictly, however, the quantity concerned is the heat of vaporization to the ideal gas state. 

In an engineering analysis, the liquid density is needed for methyl chloride (CH3CI) at 343.15 K. Determine the liquid density of methyl chloride at this temperature. 

Like alkanes, alkenes are at most only weakly polar. Since the loosely held TT electrons of the double bond are easily pulled or pushed, dipole moments are larger than for alkanes. They are still small, however compare the dipole moments shown for propylene and 1-butene, for example, with the moment of 1.83 d for methyl chloride. The bond joining the alkyl group to the doubly-bonded carbon has a small polarity, which is believed to be in the direction shown, that is, with the alkyl group releasing electrons to the doubly-bonded carbon. Since this polarity is not canceled by a corresponding polarity in the opposite direction, it gives a net dipole moment to the molecule. 

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