The synthesis, purification, and certain physical constants of the normal hydrocarbons from pentane to dodecane, of n-amyl bromide and of n-nonyl bromide

Abstract

The normal paraffin hydrocarbons from pentane to dodecane, n-amyl bromide and n-nonyl bromide have been synthesized and prepared in very pure condition. The boiling points, freezing points, and refractive indices (N 2

Separation of the aromatic hydrocarbons, and of the isolation of n-dodecane, naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene, from the kerosene fraction of petroleum

“…-Amount of liquid-soluble, solid-insoluble impurity, calculated fro m tbe lowering of the freezing point , and using for the freezing point of pure n-dodecane the value -9.60 (see table 2) and for tbe heat of fusion tbe value 8,730 cal/mole [5J. The freezing point of a given lot was taken to be the highest temperature observed with crystals present.…”

“…The properties of the best n-dodecane from this petroleum are given in table 2, together with values previously determined for this substance by Shepard, Henne, and Midgley [7] and by Mair [8]. • These values were estimated from the vaiues observed at 25° O.…”

“…As is evident from the low refractive index, the recovered oil contained little • Amount of Iiquid·soluble, solid-insoluble impurity, calculated from the lowering of the freezing point, using 80.27° C (see tahle 4) for the freezing point of pure naphthalene and 4.610 cal/mole as its heat of fusion [5]. The freezing point of 8 given lot was taken to be the highest temperatore observed with crystals present. This temperature was attained for lot 1 about 1 minute from the start of supercooling.…”

Heats of isomerization of the five hexanes

“…On a small part of each of these samples, measurements were also made of the heat capacity in the range from-1 85° to 50° C by Stull, who has r eported in detail concerning the heat capacities of the solid and liquid states, the heats of fusion for n-hexane, 2-methylpentane, and 2,2-dimethylbutane, and the heat of transition for the latter [20]. 404687--41-6 The second lot of n-hexane (labeled "B" in this paper) was obtained from B. J. Mair, of this Bureau, who has described its synthesis, purification, and properties [21].…”

“…In view of (a) the manner of preparation and purification, (b) the accord of the physical properties of refractive index, density, boiling point, and, where available, the freezing point, with the "best" values recorded in the literature [18,19,20,21,22,23,28], (c) the fact that no significant difference in heat of combustion was observed for the two lots of each of the isomers from independent sources, and (d) the fact that the impurities would be expected to be isomeric hexanes to the presence of which the measurements are not overly sensitive (see following), it may be concluded that the amount of combustible impurity in any of the 10 lots of material was such as to alter the heat of combustion by not more than 5 parts in 100,000. It would be expected from the manner of preparation and purification that the impurities are isomeric hexanes.…”