INDUSTRIAL A N D ENGINEERING CHEMISTRY ANTHRACENE L = 18624 - 8.0 ’I’ Entropy of vaporization at 518” (absolute) = Log p = 20.7103
Temp. C. 220 240 260
280
- 4066.8- 4.0223 log T
TABLEI1 ---PRESSURE--Observed Calculated Temp. Mm. Mm. O C . 42 7 300 42.6 76.0 76.1 320 129.1 129.5 340 211.0 211.0 345
’
L = 13.7 RT
Temp. ’ C. 230 250 270 280
TABLE 111 ----PRESSURE---. Observed Calculated Temp. Mm. Mm. ‘C. 58.3 58.7 290 104.4 103.7 310 173.6 173.2 330 220.0 219.7 340
232 0 502 9 732 9 799.5
474r 7*3 -
-
Entropy of vaporization a t 551O (absolute) = L = 14.0
RT
LogP=3351.3
RT
c.
= 14.4
310 320 330 340
6.7893 log ‘ I ‘
WORKS, CHICAGO, ILL.
a
While making a study of the methods in use for the determination of the acetyl value in conjunction with the Committee on the Analysis of Commercial Fats and Oils, some data were collected that may be of general interest. All the results are from determinations made on samples of the same lot of oil. The first methods to be tried out were those of the Association of Official Agricultural Chemists.2 Separating the acetic acid by filtration, four laboratories collaborating obtained results varying from 137.7 to 163.2. Separating the acetic acid by distillation, six laboratories collaborating obtained results varying from 108.4 to 165.4. The results by the distillation method were so erratic that further work was done in this laboratory to throw some light on the trouble. The method was followed in detail up to the point of distillation, where the distillate was collected in fractions, the distillation being carried much farther than usual to note results. Below is given the total volume of distillate, together with the corresponding acetyl value calculated from the total acid collected at each cut. Corresponding Acetyl Value 124.5 133.5 142.5 147.5
These figures indicated, no definite end-point, and to see if one could be reached, another sample mas run with the following results: Distillate cc.
1 Received 2
Corresponding Acetyl Value
Distillate cc.
April 2, 1923. Assoc. Official Agr. Chem., Methods, 1920, 250.
Corresponding Acetyl Value
PRESSVRE----. Observed Calculated Mm. Mm. 186.0 186.1 232.0 232.7 287.5 288.8 355.0 355.9
7 -
Pmp. C. 350 360 370 380
---
PRESSURE---
Observed Mm. 435.5 531.7 643.7 763.4
Calculated Mm. 435.6 529.3 640.3 769.4
The foregoing would indicate the impossibility of obtaining definite results by this method. The committee next tried the Andre-Cook3 method with much better agreement than either of the two previous mentioned. Six laboratories collaborating obtained results varying from 142.5 to 148.2, with an average of 145.46.
By Jesse R. Powell
Distillate c c. 500 700 900 1300
(E1 - +) + 2.16967 TABLE IV
Temp.
Notes on the Determination of the Acetyl Value’ ARMOUR SOAP
PRESSURE--Observed Calculated Mm. Mm. 276.1 276.2 424.0 425.1 629.4 629 4 757.0 756 4
L = 15347
231.1 499 8 733 0 800.3
PHENAKTHREPU‘E
-
---
ANTHRAQUINONE ---PRESSURE--Observed Calculated Mm. Mm.
L=21740.5-13.5 T Entropy of vaporization a t 517’ (absolute) = Log @ = 29.5477
Vol. 15, KO. 6
J. A m . Chem. S a c , 44 (1922),392.
Crude Rubber Committee Plans Work
,
A meeting of the Crude Rubber Committee of the Rubber Division, AMERICAN CHEMICAL SOCIETY, was held a t the Chemists’ Club in New York City, M a y 8, 1923. All the active members were present and the work of the committee was planned and organized. As a compound t o test for variation of rate of cure, the puregum stock-100 rubber and 10 sulfur-was adopted. For the evaluation of quality a formula containing 3 per cent sulfur, 30 per cent zinc oxide t o 100 of rubber, and accelerated with “hex,” was tentatively decided upon. Mr. Rose will take up the development of a breakdown and a swelling test. Mr. Van Valkenburgh will work on viscosity determinations, and determine the value of the zinc oxide-“hex” stock for test purposes. Mr. Sanderson will investigate the matter of selecting the most significant physical measurements for cure criteria, using the pure-gum test formula. Mr. Cranor will undertake to determine the relation between variation of different lots as shown in the pure gum mix, compared with the action of the same rubbers in certain practical accelerated mixmgs. The committee expects t o have a definite report for the fall meeting of the AMERICAN CHEMICAL SOCIETY.
Chemistry in the East Indies The Royal Academy of Sciences of Amsterdam has recently prepared a series of papers (in English) summarizing the development of various fields of science in the East Indies, one of which is “A Review of Chemical Investigations in the Dutch East Indies.” This is a brief and comprehensive digest of the contributions which have been made by Dutch chemists of the East Indies upon problems of pharmaceutical, agricultural, and industrial chemistry of t h a t region. Special mention is made of cinchona cultivation, the sugar industry, rubber, tea,. coffee, and tobacco cultivation, the production of essential oils, and phytochemical investigations. A supply of these papers has been sent to the National Research Council, Copies may be obtained (without charge) by addressing E. W. Washburn, Chairman, Division of Chemistry and Chemical Technology, National Research Council, 1701 Massachusetts Ave.. Washington, D. C.
