Methyl alcohol heating value

While heats of wetting for a solid in a variety of pure liquids can be informative, heat values as a function of the amount of preadsorbed wetting liquid are more desirable. The data of Table V for the immersion of bare and monolayer-covered samples of graphite illustrate the limitations of single heat measurements. The more comprehensive studies applied to the immersion of rutile in the n-butyl derivatives should furnish answers to questions concerning the nature of the adsorbed film on this solid. Indeed, preliminary measurements substantiate the assumption of an oriented monolayer of adsorbed alcohol on rutile made in Sec. V,B. Unlike water-solid systems, almost no comprehensive heat measurements have been reported for solid-organic liquid systems except that of Razouk (49) for the immersion of bare and film-covered samples of a porous charcoal in methyl alcohol and the recent work of Pierce et al. (60) on carbon-benzene systems. Such information would be most instructive. 

CH3OH (aq.). Data on the heat of solution of methyl alcohol in water were reported by Berthelot,36 deForcrand,6 7 and Bose.la The latter s data also yield values for the heat of dilution of aqueous methyl alcohol. 

The calculated heats of dissociative adsorption of water, ammonia, and methyl alcohol (Fig. 19) are also presented in Table VII. The heat of water adsorption was 61 kcal/mol (CNDO/BW) or 43.7 kcal/mol (STO-3G), and the respective value for ammonia was 38.7 kcal/mol (CNDO/BW). If the pseudo-atoms A model the lattice silicon atoms, structure (d) is somewhat... 

The specific heat of mixtures of liquids can rarely be calculated additively from the specific heats of the components. There is generally a considerable deviation from the law of mixtures, and the calculated value is always larger than one would expect. Mixtures of hquids which are closely related chemically, such as ethyl and methyl alcohol, chloroform and carbon disulphide, behave normally mixtures of water with alcohol, or of alcohol with other organic hquids, show large deviations. It is noteworthy that heat is evolved on mixing these hquids, an indication that chemical combination also is taking place. This is probably the reason for the alteration in the heat capacity, since the specific heat of liquid chemical compounds cannot be calculated additively from the specific heats of the components. The regularities shown by sohd bodies do not hold even approximately for hquids. 

The chlorination of paraffin hydrocarbons has been studied recently with the hope that natural gas and petroleum might prove a source for halogen derivatives of value in the arts. It has been shown, for example, that when a mixture of 5 volumes of methane and 4 volumes chlorine is heated to about 280" and passed over clay covered with aluminium chloride, there can be attained from 1000 cubic feet of the hydrocarbon about 50 pounds of carbon tetrachloride and 190 pounds of chloroform. Since natural gas contains methane and ethane the method may prove of value industrially for the preparation of the chlorine substitution-products of the hydrocarbons. If the chlorination can be controlled to give a high percentage of methyl chloride and if a way can be found to hydrolyze the latter in a satisfactory way to methyl alcohol the reactions will be of technical interest in the preparation of this important alcohol. 

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