WINNERS IN THIRD "WHAT IS WRONG?" CONTEST

The third contest' was in some respects the most difficult to judge of any which have been held so far. This circumstance arose out of the fact that the ohject of the experiment was not expressly stated, nor was it clearly indicated by the drawing. Several interpretations, therefore, were possible to the coutestants. One might disregard the object entirely, merely cor- recting errors in technic and stating the product which would be obtained by a process of distillation. One might assume that the object was to purify NHIOH by distillation, or to derive ammonia from NH40H by heating, or to obtain liquid ammonia from NH40H. Some contestants assumed that the object was to prepare ammonia and suggested an entirely diierent process. Another chose to prepare pure water from NHIOH solution and added sulfuric acid prior to distilling.

We believe that the first three methods of dealing with the problem are on the whole the most logical, and, with one exception, the winners have been chosen from among the contestants who adopted one of them. The exception receives an award because his paper constituted one of the best written criticisms of the original drawing and was accompanied by a dia- gram of fairly good appearance.

None of the contestants who elected to prepare l iquid ammonia described or pictured an entirely practical apparatus, although several suggested cooling mixtures which should he capable of condensing ammonia a t atmospheric pressures.

Several coutestants suggested practical methods of drying ammonia gas, hut one suggested the use of CaCll which would not he suitable. [See THIS JOURNAL, 6, 1777 (Oct., 1929)l.

A number of contestants failed to note that the placing of the ther- mometer would differ, depending upon whether NH40H solution was to be distilled or NH1 was to be driven off by heat.

As heretofore, greatest credit was given for observations relating to correct laboratory technic and to chemical facts. Criticisms of objects wrongly represented were also credited, provided that they touched upon points more fundamental than mere drafting technic. Greater weight was attached to statements accompanied by reasons than to bare assertions. The correctness and appearance of drawings played a large part in the final distribution of awards, since many coutestants received nearly the same score on their written criticisms.

Robert C. Schmitz, of Milwaukee, Wisconsin, outpointed other com- petitors by a slight margin. His paper and drawing are reproduced here- with.

The drawing is imperfectly made, that is; thelines of the ring stands are not uniform. There are lines drawn through the gas hose and other passages in the drawing, and the ring stands are not drawn in proportion to the other apparatus.

' S e e THIS JOURNAL, 6,2262-3 (Dec., 1929). 438

THE CHEMISTRY STUDENT

There is no stopper in the flaskcontaining ammonium hydroxide, therefore the

of the flame. The Runsen burner has no air holes, therefore a luminous flame will be the result.

This kind of a flame is undesirable, because the flame is not as hot as the n o n - l ~ ~ o u s

440 JOURNAL OF CHEMICAL EDUCATION FEBRUARY, 1930

flame and due to the lack of oxygen the carbon is not completely oxidized and will con- scqnently deposit on the flask.

In the drawing there is no asbestos gauze under the flask to prevent the flames from coming in direct contact with it, which may result in cracking the flask.

The thermometer, which, in the drawing is wrong side up, should be placed right side up in the solution and constantly observed, so that the temperature will not ap- proach that of boiling water.

Ammonium hvdroxide is an unstable basic solution and the slight amlicatian of heat . .. will drive off the ammonia gas. This gas being lighter than air will rise and pass up into the collectina bottle. The delivery tube is extended high up in the collecting bottle to . - -

prevent the ammonia gas from mixing with a large amount of air. The gas will force the air out of the hole C, as shown in the accompanying drawing.

There is no stopper in the collecting bottle, thereby letting the ammonia gas escape into the atmosphere.

In the drawing the water is shown entering the condenser a t the top, which is im- proper. To keep the condenser properly filled with water, the supply should be intro- duced at the lower opening and expelled from the upper.

The drawing shows the ammonia gas in a liqnid state within the condenser and collecting bottle. It also shows the collecting bottle in ice water. It is impossible to have the ammonia in a liquid state under these conditions, for ammonia has a boiling point below zero. For this same rearon the condenser and beaker of ice water are super- fluous in this experiment.

Winners of the five one-dollar awards were: Hubert Rivers, Hutchinson, Kansas; Richard Kocher, Allentown, Penna.; Esther Elking, Dayton, Ohio; Virginia Mary Weber, Dayton, Ohio; Dwight Santiago, Aguadillo. Porto Rico.

American Rocket Experimenter Amounces New Liquid Propellant. Dcvelop- ment of a liqnid propellant for rockets that will make possible airplanes much faster than those of the present day is announced in an article prepared for Science Sfrvice by Prof. R. H. Goddard, of Clark University, Worcester, Mass. Commenting on the recent experiments in Germany with a rocket propelled airplane, he said:

"The recent racket plane flight in Germany raises the question as to just what bearing this result may have on aviation. According to German aeronautical journals, these rocket auto and airplane experiments are being carried out along the lines of the experimental work that I performed a t Clark University in 1916 and which was pub- lished by the Smithsonian Institution in 1919.

"These published results described expansion nozzles of eight degree taper, elec- trical ignition by wires through these nozzles and the system of using bundles of similar rockets, all of which are now in use abroad.

"A plane equipped with powder rockets, however, has an extremely limited cruis- ing radius unless i t is used as a rocket glider. If, on the contrary, liquid propellants are used, capable of supplying a large amount of energy compared with an equal weight of powder and the amount of propellant carried is large compared with the weight of the rocket plane itself, some very surprising distances can be covered in a much shorter time than with an ordinary plane. The development work on liquid propellant rockets planned abroad is unnecessary as my work under the Smithsonian Institution has al- ready produced liquid propellant rockets that operate."-Science Senice