The adsorption of nitrogen, oxygen and argon on rutile has been investigated a t liquid nitro en and oxygen temperatures in the region of low relative pressure. A t a iven value of p / p~ the amount of nitrogen adsorbedggreakly exceeds the uantity of oxygen or argon adsorbed. The distri%ution of adsorption energies among surface sites has been compute.! and is shown to differ with each adsorbate. The reasons for these differences and the usefulness of the concept of surface heterogeneity are discussed.

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In a previous publication (1) a method was described which made it possible to study the sorption of bromine and iodine by porous adsorbents over a rather wide pressure range a t several temperatures. At that time the sorption of bromine and iodine by silica gel at several temperatures was reported. Equilibria for adsorption and desorption were established rapidly in the case of silica gel. In the present study on charcoal equilibrium was reached slowly, so that rates of sorption were measured in addition to the determination of the amounts taken up a t equilibrium.The charcoal used in this investigation was prepared from coconut shells. Broken coconut shells were cleaned and then placed in a large Soxhlet extractor where they were successively extracted for prolonged periods with ether, alcohol, and finally water. The extracted shells were coked in a covered iron crucible in a sand bath. The temperature was raised slowly to 550-575'C. and held there for half an hour after the last flammable vapors came off. After cooling the charcoal was crushed and sieved. A portion of 25 g. that passed a 10-mesh and was retained by a 20-mesh sieve was taken for activation. This was packed in a clean silica combustion tube and heated to 850'C. in an electric furnace. Superheated steam from a small boiler was passed over the charcoal for thirty minutes. After cooling, the average loss in weight on activation by steam was found to be 25 per cent of the initial weight. The steam-activated charcoal was then placed in a silica tube and heated to 700'C. while it was evacuated with a pair of Langmuir condensation pumps. The charcoal was protected from mercury vapor by a liquid air trap. After a 24-hour evacuation the charcoal was cooled to room temperature and oxygen admitted. After standing some time in an atmosphere of oxygen the charcoal was again heated and evacuated for a period of 48 hours. The charcoal was then cooled in an atmosphere of nitrogen. On ashing in a platinum crucible the following results were obtained: ash, 0.185 per cent; ash as sulfate, 0.233 per cent; silica, 0.026 per cent.The charcoal was crushed in an agate mortar and that portion used which passed a 60-mesh and was retained by a 100-mesh screen. About 0.2 g.

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The chlorination of the paraffin hydrocarbons has been the subject of many investigations. Most of the chlorination studies have been concerned with methane and natural gas in the hope of obtaining important and useful products. The literature resulting from these investigations has been well summarized by Egloff, Schaad, and Lowry (2). Much of the work to date has been qualitative in nature and there are many patents which claim to be able to produce any one of the substitution products by a variation in the conditions of the reaction. A good deal of study has also been devoted to the effect of different catalysts.Since the quantitative side of the chlorination problem has been largely neglected it was felt that such a study from the standpoint of kinetics was highly desirable. The results obtained would be of theoretical interest in addition to possible practical applications. The latter results would be of particular value in this country, where such large quantities of the lower paraffin hydrocarbons are available.The following investigations give the results of quantitative studies on the chlorination of propane. The work was divided into studies on the homogeneous and the heterogeneous reaction. Propane was chosen as the chlorine acceptor because (1) it is the simplest hydrocarbon having a secondary carbon atom, (2) it is the simplest paraffin hydrocarbon all of whose chlorinated products are liquids at room temperature, and (3) it is readily available in a state of high purity. APPARATUS AND MATERIALSThe reacting gases were passed through purification trains, drying tubes, flowmeter, and mixing chambers before being admitted to the electrically heated reaction zone.The products were condensed in a trap placed in a 1 The material here presented formed a part of thesis submitted to the Graduate Faculty of the University of Minnesota by Samuel Yuster in partial fulfillment of the requirements for the degree of Doctor of Philosophy, March, 1934.