A SUCCESSFUL OPEN-HOUSE PROGRAM M. MERLKINDY.FRANKLIN HIGH SCHOOL. LOS ANGELES. CALIFORNIA
A n open-house evening gi~esthe chemistry teacher a splendid opportunity to sell his subject to the community. Most other departments are limited to "dead" exhibits. A "he" chemistry Program combining pure entertainment with interesting practical demonstrations will be found to steal the c r d s from the other depaartments and create enthusiasmfor the subject. Such a program, puc on i n the chemistry laboratory at Franklin High School, was visited by approximately one thousand people.
. . . . . .
An "open-house" evening gives the adults a chance to visit the school, meet the teachers, and does much toward creating a friendly feeling between the school and the public. Chemistry teachers, in particular, have a splendid opportunity t o create interest and enthusiasm in their subject. The question of what to show the people is naturally an important one. Unless the exhibit is alive and full of action, the people are apt to feel bored instead of enthusiastic. Our school has had open house as an established annual custom for a number of years. It has been necessary for the chemistry department to evolve some successful plan for giving the people what they like best. We have tried practically every idea that has come to our attention. One year, regular classes were held with parents visiting. Another year, we had studerits performing typical laboratory experiments. The people were only mildly interested. We have featured posters, special projects, and other ideas. For several years we have required each student who takes part in the open-house program to write up exactly what he did, and include the people's reactions, such as questions asked, comments overheard, and interest displayed. He is also asked to submit suggestions as to how his part might be improved. The teachers also have made note of where the crowds seemed to gather, and in talking with parents have watched for comments which indicated the part of the program they were most interested in. We thus have on paper a large number of ideas which have been used in the past, and this year we were in a position to select the best. No claim is made that the experiments described are original. In fact, many are so old we don't know the source of the idea. Many of the old experiments, however, have been slightly modified to make them more effective foradult entertainment. Theonly thing weclaim is to havestudied rather carefully the psychology of the public, and to have given them this year a demonstration with enough action that none became bored. Each student selected the experiment he wished to try, and most of them were given rather complete directions from previous years. Consequently, the whole proham was worked up with a minimum of labor and confusion. 2046
VOL.8, No. 10
OPEN-HOUSE PROGRAM
2047
Approximately one thousand people saw the complete list of demonstrations. The program lasted from 7.00 P.M. until 8.45 P.M. In order to handle this large crowd we had arranged an orderly line of march which led past each demonstration. As the people first came into the room they were greeted by a sight which caused them to rub their eyes and look again. The sign read, "The Original Fire Water," and there sure enough was genuine water running from the faucet, burning merrily. An ordinary aspirator was screwed into the faucet, but the rubber tube leading to a distant gas jet was so cleverly concealed that few saw it. Moving on, the people next came to an exhibit of glass etching done by one of the chemistry students. For amateur work, her pictures were unusually good and produced much favorable comment. Any student who had studied ionization could answer the next sign, "What Makes the Lamp Light?" but most of the grown-ups were still wondering when the evening was over. When they saw that shaking a little salt from an ordinary shaker into the distilled water made the lamp light, they were suspicious that there was a concealed switch somewhere. The only way to convince them that there was no trickery was to let them try it themselves. The people have always been interested in the display of home-grown crystals. Viewed through reading glasses, the copper sulfate, sulfur, salt, alum, and Rochelle salt crystals were attractive enough to cause every one to stop and marvel. Some of the best displays of crystals were those which were purely accidental. One of the teachers prepared a salt solution for a sore-throat gargle and forgot to empty the beaker. A few weeks later some beautiful cubes were found in the dry beaker. A student forgot about a solution of copper sulfate and alum until she found the two almost completely separated into perfect crystals some days later. An artist could scarcely have planned a prettier pattern. Among the best of the crystal displays was the basket of "jewels," made by suspending a thread basket in an alum solution. Coming to a student who was changing water to cherry punch and back to water again, most people of course suspected that the wet beakers contained some chemicals which were causing the color changes. The next demonstration however had them stumped. Here a red potassium permanganate solution was poured into a clean, dry, "empty" bottle, and became colorless instantly. No one could see the sulfur dioxide gas which partially filled the bottle. The student in charge of the generator was some distance away, and was bleaching colored flowers in addition to filling bottles for the potassium permanganate demonstration. Next was a surprise lesson in dyeing, for the people saw red litmus paper, dipped into a red solution, come out blue, and blue litmus paper, dipped
2048
JOURNAL OF CHEMICAL EDUCATION
OCTOBER, 1931
into a blue solution, come out red. The blue solution was copper sulfate. The "chemical" cake, and "synthetic" punch, have become an openhouse tradition a t our school. Girls are eager to volunteer to make the cakes, and we always have a large number of large cakes on hand when the people begin to arrive. Although each visitor is given only a mouthful for a sample, we never have had enough for all to get a taste. The cakes are made using any simple cake recipe, but substituting a calculated quantity of concentrated hydrochloric acid and soda for the baking powder. The public never ceases to marvel that cakes made with concentrated acid are good to eat. Near where the cake and punch were being served were two girls using an apparatus to measure the amounts of carbon dioxide liberated by various brands of baking powder. The apparatus was similar to the one described in many laboratory manuals for determining the percentage of oxygen in potassium chlorate, except that a flask and dropping funnel replaced the test tube. A series of signs set forth the facts about baking powders, and the girls were glad to offer further explanation to any who were interested. A little farther on were two girls with a reflux distilling apparatus, preparing fragrant esters. Samples of previously prepared ethyl acetate, amyl acetate (banana oil), and methyl salicylate (wintergreen) were given the people to smell. Most folks were interested in the odors if not in the apparatus. Next to catch the attention was a magic pitcher which was being used to pour out water of almost any color desired. The students were specializing in red, white, and blue. The beakers were first filled with water from the pitcher, then two a t a time were emptied back into the pitcher. When again poured out the water was colored. I t is not difficultto find pairs of ions to produce almost any color. As the people passed a vessel containing carbon dioxide snow, they were invited to take some. The extreme coldness startled all of them. A very dramatic experiment, if properly done, is the solidifying of alcohol and a calcium acetate solution. The two liquids suddenly harden about twenty seconds after being poured together. The student found by practice that he could pour the mixture back and forth between beakers about twice, having his motions timed so that the third time he inverted the beaker, the mixture had solidified and did not come out. The watchers' mouths literally drop open as they wonder what has happened to theliquid. It is more effective in this, as well as other demonstrations for entertainment, to call all colorless solutions water. The people are further surprised when they see this water bum. Passing again from the ridiculous to the sublime, the people came to an exhibit of simple student projects, with samples of the original and final products in each case. One student had removed the scale from a tea-
VOL.8, No. 10
OPEN-HOUSE PROGRAM
2049
kettle, had purified it and exhibited the pure while calcium carbonate, which he was explaining was useful in tooth pastes. Another had changed some brown cadmium oxide (which had been in the storeroom for years and never used) to useful white cadmium chloride. Still another was showing a sample of pure salt, which had been recovered from the crust along the shore of the Salton Sea, in Imperial Valley. The purified salt presented quite a contrast to the dirty crust, and was pure enough, that even though made months before, it had not caked in the slightest degree. Although the next experiment was of no practical value, the women, in particular, were quite impressed. Some "chemical jello" which hardened in a few seconds, was being made from water glass and hydrochloric acid. Turned out of ordinary jello molds and colored with various indicators, the samples looked so attractive that the people had to be told not to eat them. A teacher's office was used as a passageway between two laboratories. This had been converted into a beauty spot. Using a water-glass solution and crystals of colored salts, a student was growing beautiful chemical "flowers." Silver and lead "trees" were growing in tall graduates between these beds of flowers. Expressions of admiration were frequently heard. The only trouble with this exhibit was that people wanted to linger too long in this chemical garden. Entering the next laboratory room the visitors were again made to doubt their eyesight. Here was a water faucet clamped to a ringstand with a full stream of water pouring from it, coming apparently from nowhere. Of course, the sign said it was being condensed by radio from the air, and there was a miniature aerial connected to the ringstand, but that seemed hardly possible, even in California. A fortunate circumstance had occurred, which gave the student in charge a chance to enlarge on this idea. A record dry spell had been broken by a heavy rain the day of open house (when this apparatus was set up) and it was still raining that evening. Some people stood as long as five minutes trying to solve the mystery of this water, without seeing the glass tube coming up from below and entering the faucet. The water coming down on the outside of the glass effectively concealed it. A simple experiment that is always sure to attract attention is the one which we called "Educated Moth Balls." Tall cylinders of water are seen, with moth balls ceaselessly rising and sinking. The balls are floated, either by bubbles of hydrogen, or carbon dioxide, made in very small quantities by the action of sulfuric acid on either zinc, or sodium carbonate. When they reach the top, the balls turn over, lose the bubbles of gas and slowly settle. The next exhibit was one of silvering mirrors. Using one of the standard formulas, some students were silvering test tubes, watch glasses, beakers, and flasks and succeeded in getting some splendid results. One of the prize demonstrations came next. Using the well-known iodic
2050
JOURNAL OF CHEMICAL EDUCATION
OCTOBER, 1931
acid time reaction, two students were promising to make their solutions flash hlue a t precisely the end of any number of seconds asked for. This experiment was performed about thirty times that evening, with times ranging from seven t o forty seconds, without missing the time more than one second all evening. A previously prepared graph told them the exact amount of water to add to delay the reaction any length of time. An amusing illustration of how it is almost impossible to predict what stunts will go over best was illustrated in this experiment. The students had secured a seconds pendulum from the physics department, and had arranged an electrical connection so that seconds were ticked by a telegraph sounder. This was installed only as a simple timing device, hut the public found it about as interesting as any of the demonstrations. More than one insisted that the two dry cells were causing the pendulum to swing. A sign, "Why Die? Get the Mechanical Heart!" was used to attract attention t o a mercury heart, which kept up its mysterious heating all evening. The well-known fire-writing stunt, where a spark of fire traces out any writing or picture previously made with a potassium nitrate solution, has always proved popular. This year two girls had prepared a number of clever cartoons. The used sheets were mounted over the blackboard, so that when the evening was over, all the cartoons were on display. One showing an old man trying to hit a golf hall was worthy of a prize. An interesting experiment, whose glory was only slightly dimmed by some of the other demonstrations, was the ammonia fountain. By the time the people had reached this experiment, they were so used to the unusual, that they were partly prepared to see the water race uphill and change from red t o hlue. The race between the hlue and gold was very pretty, and attracted attention even though it came near the end of the exhibition. Advantage was taken of two time reactions, the iodic acid reaction which flashes blue, and the arsenious acid reaction which turns to a beautiful gold. The two solutions were prepared so that each reaction occurred in about twenty seconds. After the respective solutions were mixed in beakers, they were poured into large test tubes, on foot, and set up where all could see the finish of the race. The last demonstration was the painting of pictures, in four colors, by spraying a solution of ferric chloride on an apparently blank paper. The papers had been previously prepared by painting with solutions of potassium thiocyanate, potassium ferrocyanide, and tannic acid, and drying. When mounted on an easel, and the ferric chloride solution sprayed on from an atomizer, a picture formed which was red, blue, gray, and white. Students were selected for this demonstration who had some artistic ability, and it was really surprising to see some of the splendid pictures they were
VOL.8, NO. 10
OPEN-HOUSE PROGRAM
2051
able to produce. This demonstration proved to be a fitting finale for the visitors. The open house described above proved to be a huge success. It seemed to combine a happy mixture of the foolish and serious. Every one had a good time, students, teachers, and visitors. There were no dull spots in the list of exhibits. We have learned a t this school that the public does not attend open house to be educated. We instruct the students in charge of the demonstrations to be sure they understand the chemistry of their experiments, to avoid possible embarrassment, but to make no attempt to bore the public with an explanation, unless i t is asked for. A little semi-foolish "chatter" pleases the people better. It might be argued that the demonstrations described give the public the wrong impression of what we teach the students in school. We have not found it so. The parents understood that this did not represent typical class work, and none of them demanded that we show them that. The writer visited another open-house demonstration recently, where the experiments were all typical laboratory experiments. Students were preparing hydrogen, oxygen, testing for chloride and nitrate ions, etc. None of the people knew what a chloride or nitrate ion was, and their expression indicated that the students might just as well be trying to bum water. Getting ready for the open-house demonstrations upset the regular chemistry classes for about two days. These two days were valuable, however, because teacher and pupils were "playing" together, and getting better acquainted than in a whole semester of class work. The pupils found the whole program a lot of fun and many entered into the regular class work with a new zest.
