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T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
Vol. 13, No. 6
A New Type of Electrolytic Cell' By Hiram S. Lukens JOHN
HARRISON LABORATORY OF
CHEMISTRY, UNIVERSITY O F P E N N S Y L V A N I A , PHILADELPHIA, PENNSYLVANIA
I n attempting t o study t h e influence of t h e electric current on suspensions of insoluble or sparingly soluble substances in various electrolytes, i t was found t h a t t h e literature of t h e subject offered few suggestions for maintaining uniform suspension of t h e insoluble substance throughout t h e electrolyte. The t y p e of cell t o be described has proved most satisfactory for t h e study of t h e electrolysis of such suspensions as t h a t of nitrobenzene in dilute sulfuric acid, benzene a n d toluene in dilute sulfuric acid, anthracene in dilute sulfuric acid, etc., as well as for t h e electrolysis of electrolytes in which all of t h e constituents were in complete solution. The cell is of t h e two compartment type, t h e outer vessel, constructed of a suitable metal, forming t h e outer Compartment, as well as serving as one electrode. A porous cup serves as t h e inner compartment, t h e walls acting as a diaphragm separating t h e anode a n d cathode liquids. The principal novelty of the cell consists in t h e construction of t h e inner electrode within t h e porouscup. This electrode, which may be either a n anode or cathode, depending on whether an oxidation or reduction process is t o be studied, was constructed as follows: A sheet of the metal desired, 1 t o 2 mm. in thickness, was cut t o a rectangle of such size t h a t t h e longer dimension represented t h e circumference of a cylinder t h a t would fit loosely within t h e porous cup. The shorter dimension represented several millimeters less t h a n t h e height of t h e porous cup inside. Using a chisel of appropriate width (about 6 mm.), t h e sheet of metal was t h e n cut as indicated in Fig. 1. It will be noticed t h a t t h e sheet is thus divided into small rectangles cut through the metal on three sides. Alternate rectangles were then bent out t o opposite sides of t h e sheet so t h a t they formed an angle of about
T h e electrode so constructed was made fast t o a circular plate of lead (about 4 mm. in thickness), whjch served as cover-plate for t h e porous cell. A circular hole, 2 5 mm. in diameter, was cut through t h e center of t h e cover-plate, in which was inserted a cork which
sf -Hard Rubber Coflar
Porous
-
cup Confainmg Vessel Oufer €/ectrode
-Inner f/ectrod e
_ ........ .. - ::..:.
.... . :.. -
~
e.
FIG.
2
served as mounting for t h e mercury seal device through which a stirrer passed. The stirrer was of glass, bent 77773177777777717712 as indicated in Fig. 2. T h e stirrer was rotated in such 77777771773377717713 a direction t h a t t h e contents of t h e inner cell flowed 7 7 7 7 7 7 7 7 7 1 3 3 J 7 7 7 1 7 7 1 against t h e open end of t h e fins on the electrode a n d 77777117137777777773 flowed alternately in and out of t h e passages created 7 7 7 7 7 7 7 3 7 7 7 7 7 J 7'7 7 7 7 Z b y t h e openings under t h e fins. At a stirrer velocity 77777771737177717737 of 500 t o 700 r. p. m., t h e suspension was entirely J 7 3 7 7 I I 7 7 7 7 7 7 1 3 7 7 7 3 7 2 uniform from top t o bottom. This was ascertained 7771777J777777777777 by testing t h e efficiency in a glass beaker, of t h e same 3 7 7 7 ~ 7 7 7 7 3 7 3 1 7 7 7 7 7 3 3 dimensions as t h e porous cell. 7777777177Il377717377 T o close t h e inner compartment and render i t gas3 3 3 3 1 7 7 7 3 3 7 7 7 7 7 7 1 7 3 = tight, a hard rubber collar, 2 mm. in thickness a n d Il7777377777II33717177 5 5 mm. in width, was fitted t o t h e edge of t h e circu a r 7 I I 7 7 ~ 7 7 7 7 Z l 7 7 3 7 7 3 3 3 7 lead ~ cover-plate, as indicated in Fig. 2 . When t h e level of the electrolyte i n t h e outer compartment was 7 7 7 7 7 7 7 7 7 7 7 7 3 3 3 3 3 3 3 7 7 7 3 3 7 7 7 7 7 7 7 7 1 7 3 7 7 3 7 ~ brought above t h e lower edges of t h e rubber collar, t h e inner compartment was rendered entirely gastight, 7377Zl777777777333777 a n d any loss occasioned by t h e diffusion of gas through t h e unimmersed portion of the porous cup was eliminated. A vent was provided b y means of a cork a n d t u b e through t h e cover-plate, as indicated in Fig. 2 . This cell is now in use in t h e study of several electrolytic oxidation a n d reduction processes.
June, 1.921
T H E J O U R N A L O F I N D U S T R I A L AATD E N G I N E E R I N G C H E M I S T R Y A D V A X T A G E S OF T H E C E L L
.
The cell has the a d v a n t a g e s of being easily assembled and dismantled for t h e removal of electrolyte. Gas loss b y diffusion t h r o u g h the porous cell is entirely eliminated. T h e electrodes a r e b r o u g h t close together, t h e r e b y reducing t h e voltage d r o p t h r o u g h t h e electrolyte. T h e efficiency of reaction of anodically liberated oxygen or cathodically liberated hydrogen, as t h e case may be, m a y be conveniently s t u d i e d at v a r y i n g c u r r e n t densities by observing t h e amount of gas escaping t h r o u g h t h e v e n t - t u b e u n d e r t h e conditions being
studied.
Water Heater for Analytical Work1 By S.L. Meyers SOUTHWESTBRN PORTLAND CEMENTC o , VICTORVILLB, CALIFORNIA
T h e h e a t e r herein described h a s t h e a d v a n t a g e s over the ordinary hot w a t e r bottle t h a t t h e only a t t e n t i o n needed is in refilling t h e reservoir, t h e force of t h e washing s t r e a m is supplied by gravity, and n o blowing is
necessary. The heater, shown in section in t h e d i a g r a m , consists of a copper or brass cylinder of a b o u t 1OOO-cc. capacity, closed at each e n d except for connections. T h e cylinder is insulated with s h e e t mica, around which a r e wound 25 f t . of resistance wire, a n d t h e whole is covered with asbestos. The wire is a G e r m a n silver wire, 0.057 in. in diameter (B & S gage 015). A further 5 ft. of this wire is wound r o u n d the t u b e which carries t h e w a t e r f r o m the h e a t e r t o the washing s p o u t , t h u s preventing the water in the tube f r o m becoming cool on standing. T h e r e is no d a n g e r of overh e a t i n g the rubber t u b i n g if t h e h e a t i n g element is i n series with a hot p l a t e or lamp i n an o r d i n a r y lighting circuit. The resistance wire a r o u n d t h e r u b b e r t u b i n g is covered w i t h a light cotton cloth i n order to avoid d a n g e r f r o m exposed live wires. W a t e r e n t e r s t h e lower e n d of t h e h e a t e r , a n d t h e a i r e v o l v e d on h e a t i n g passes o u t t h r o u g h t h e air escape i n t h e t o p of t h e a p p a r a t u s . T h e elastic t o t h e ceiling serves to s u p p o r t t h e weight of the lower tube and t o increase t h e ease of manipulation of the washing spout. The National Research Council has formed an Alloys Research Association to furnish an informational service concerned with metals and their alloys. It proposes to supply information as to current literature, discoveries, etc., and references and abstracts of all known information upon a given subject.
--I
Received February 24, 1921
563
Bureau of Employment of the New York Chemists’ Club The annual report of the employment bureau connected with the New York Chemists’ Club for the year ending April 30, 1921, clearly reflects the state of chemical industry a t the present time. To quote: Although the year 1919-1920was none too favorable, taken as a whole, yet 1920-1921 makes its predecessor seem easy in comparison.* * During the past year we have registered 920 men who never before have been on our lists and 606 former registrants have returned t o the active list, With such numbers of men to aid, it is easy to see that many must be disappointed when it is said that a t the end of April we had only 85 positions on file and of these many are practically withdrawn or impossible to fill.
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The recompense of the chemist has not declined but is above pre-war level, as shown by the following comparisons: In 1915 and 1916 more than 50 per cent of the calls filled were a t salaries under $1000 a year; in 1917 and 1918 less than 37 per cent were under $1000 a year; while in 1920-1921 only 4 per cent are under $1000 a year, 43 per cent are from $1000 to $1800, 35 per cent from $1800 to $2500, and 18 per cent a t $2500 or more. We note that out of 800 men registered a year ago, only 24 per cent said they would take positions paying less than $1800, 38 per cent wished $1800 to $2500, while 38 per cent would not work for less than $2500. One hundred and ninety-three for one reason or another were not classified. This year, out of 1179 registered men we find that 26 per cent will work for less than $1800, that 38 per cent will accept $1800 to $2500, and 36 per cent want $2500 or more. We therefore conclude that in these less active days those who do receive appointment will not work for materially less. Another phase repeatedly brought to our notice is the decrease in willingness to consider the employment of woman chemists. This is unfortunate. Those who have employed them report that they are uniformly satisfactory and in some ways more desirable than men, especially for routine work. It is only natural that the demand should fall off under present conditions, but the Bureau wishes to call attention to the fact that women’s colleges have in the last five years greatly improved their chemical departments and much better trained chemists are now graduated.
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In cooperation with Drs. Parsons and Howe of Washington, the Bureau is attempting to establish the status of the chemist with the Bureau of Immigration.* * * I n this Bureau we are not classed as a “professional” group. Lawyers, clergymen and physicians are allowed to enter the country under contract, but chemists are not, unless they receive $25,000 or more, or can be shown to be able to do work which no one already in the country can do.* * * The discrimination particularly affects the free movement to and from Canada. The Bureau filled approximately 38 per cent of the positions received during the calendar year 1920. This is about an averL age record.
American Institute of Chemical Engineers Plans for the Thirteenth Semiannual Meeting of the American Institute of Chemical Engineers, to be held in Detroit, Michigan, June 20 to 25, 1921, promise a meeting of great interest. Headquarters will be a t the Hotel Statler. The opening meeting a t the Hotel Statler will include papers on the relation of the chemical engineer to the auto industry, automobile finishes, pyroxylin artificial leather, and monel metal. The afternoon will be devoted to a visit to the plant of the Cadillac Motor Co. Tuesday, June 21, will be spent a t the University of Michigan, a t Ann Arbor, where several papers will be presented a t the afternoon session. Wednesday will be devoted entirely to excursions, to the Ford River Rouge plant, and to the plant of Hiram Walker & Sons, Ltd., Walkersville, Ont. The presentation of papers will be continued on Thursday afternoon, and the two remaining days of the convention will be devoted entirely to optional visits to manufacturing plants in Detroit.
