edited by

chemi~try for kid/ PATRIC~A J SMITH United States A r Academy High School Unwd States A r Academy. CO 80840

Summer Chemistry for Fun Kevin D. Hufford Broame Communily College Binghamton. NY 13902

Rarelv is chemistrv introduced in elementarv education. Many eiementary sihool teachers do not see ways that chemistry could be easily included in their curriculum. This could he overcome if the teacher could learn to perform safely some reasonably hasic demonstrations and laboratory ex- periments which would teach basic chemical principles to the students.

Rroome Community Cdlege has developed a summer non-credit program that has courses specifically designed for children in elementary and junior high school programs. The college publishes a non-credit-course brochure each fall, spring, and summer semester, which is distributed by mail to the community. The college also employs radio advertising to announce the brochure and courses.

I.ast summer 1 had the opportunity to rIe\.elop and teach a five-week col~rse c l i , hourr. ver week, entitlrd "Mr. Wiznrd: Chemistry for ~ ~ t l s . ' " ~ h i i u, i i presented to hur t h and fifth erade students. Kach session mnsisted of a h r id lecture. n iemonstration, and one or more laboratory experiments. he sources of some of the demonstrations were a hook. "Chemical Magic," by Ford' and the Hroumr ('ommunit? Colley 1nhc1- ratorv manunl. '~Exp~rimrnts In (;rntwiI ('hem~strv."Tht.re are other sources oftested demonstrations such as'books by Alyea and Duttonz and Chen."

T o have the children obtain the real feel for the fun of chemistry it was necessary to provide them with hands-on . . experience. In doing this, safety goggles were required as eye protection4 as was specified in the course description. For some demonstrations and experiments it was also~necessary that the classroom facility have adequate ventilation hoods.

' Ford. Leonard A,. "Chemical Magic." T. S. Denison and Co., Inc.. Minneapolis, MN, 1959.

Alyea, H. N. and Dutton, F. D.. "Tested Demonstrations in Chem- istrv." 6th ed.. Division of Chemical Education. Easton. PA. 1965. . . ' Chen. P. S.. ' Enlerta ning and Eoucarional Cnem cal Oemonstra-

tions.' Chemfca Elemenls Pab mhmg Co., Carnarn lo. CA. 1976. 'See OShA Law No. 1910.133 and ANSI safely code 187 1. The

goggles used in the BCC non-credit course were of the hooded-venti- lation type.

Adapted from P. D. McCormick, Thoroid Secondary School, Tho- rold, Ontario. Canada.

Before startins their lahoratorv work the students were informed as to the safety requirements for the use and han- dling of each reagent that was to he nsed. This was received well by the students. Their awareness of safety was revealed by the many questions that they asked concerning the safety of chemicals in their homes. I t is necessary that any teachers who ulan to use the cited references he aware of safetv factors. The'literature does not always provide information on safety.

Chemistry for Kids

Class 1 Title: Dissdving and Recovering Copper Metal Concept: To illustrate the law of conservation of mass.

Cu(4 - Cu(N0Maq) - CuC0:ds) - CnClz(aq) - Cu(4

Class 2 Title: Royal Fireworks Concept: To show the reactivity of elements and compounds; some

element and compounds showed little reactivity upon heating but in combination some exeitine results were observed.

Class 3 Title: The Diffusion of Metals and the Prepma6011 of Nylon Concept: Part 1-To show the diffusion of metals and ions.

a) Instructor demonstration-growth of a silver tree. b) Experiment-the zinc plating of copper and subsequent for-

mation of hrass hv heatine."

This feature is desianed to encauraae our readers to become involved on sane v a y wm mm&c ng chemnsoy to ch ldren Methms 1pennlq.es a d loeas lhal have proven succesrlu w i be featwed W e r rh to cnallenge those of yo. who have nleracted wrh cnem#rlryana ktds to share your program with the rest of the readen. We further challenge mOSe who have not made the f i s t step to use these programs to develop a System which will work tor you and the kids in your community. Re- sponses of the children to the activities would be of particular interest. In this way, this feature can provide mechanism far introducing mare chemistry to children and thus to society

Volume 61 Number 5 May 1984 427

copper token with zinc and then with direct heating transformed it into a brass token.

Concept: Part 2-To illustrate the formation of a polymer by forming nylon.

This demonstrationfiahoratory experiment has been entitled "The Nvlon Rooe Trick." Bv oreoaring nvlon the students were able to .. . s&dy some of its physical properties.

Class 4 Title: Heat Transfer, Flaming Handkerchief, and the Expansion of

c9.m Conrepr. Part l-Boiling wnlpr in a paper cup: the principle of heat

t m n ~ transferred to the wnter is rllustrated when the paper cup does not burn. The heat rapacity of HzO is greater than that of the paper.

The students formed a paper cup or box and then boiled water in it aver an open Bunsen hurner flame. Concept: Part 2-The flaming handkerchief illustrates the principle

of evaporation and the low burning temperature of alcohol. The students prepared a small handkerchief and an alcohollwater solution that ignited hut did not burn the cloth. Concept: Part 3-This demonstrates the expansion and force of a

contained gas. The students prepared a test tube with sodium carbonate, added acetic acid, corked the test tube and watched. This experiment has been called a "Chemical Cannon."

Class 5 Title: Acids and Bases Concept: Part l-The illustration of the reactive properties of acids

and bases and which substances dissolve. The students used small quantities of HCl and NaOH to test the dissolving properties of some common materials. Concept: Part 2-To test materials for acidic or basic properties. The students used universal pH paper to test common food items, - ~~

water, etc. Concept: Part 3-To illustrate the various.color changes of pH indi-

cator solutions. The qttidpnts added a variety of pH indicators ro HCI and NaOH tc, determine r h ~ rulm changes.

Details of Class 3 Port I , A. Demonstration of the Silver Crystal Tree Procedure: Pour 400 ml of 0.1 MAgN03 into a 600 ml beaker. Using

copper wire make a large, coiled shape and lower this into the silver

solution. Allow this to stand, undisturbed, where the students can observe it throughout the period.

Explanation: Points to be discussed (1) As the copper dissolves the silver forms crystals on the surfaces

of the wire. (2) The solution becomes blue because of the capper ions. (3) The silver is originally black, and finely divided, hut eventually

forms bright, shiny, Large crystals. Be sure to bring the students' attention hack to the demonstration for observations at various times in the class period. Port I , B: Capper - Silver - Gold; Alchemy a t Work Procedure: In an evaporating dish place a small amount of zinc dust

(use a spatula). Carefully add 3-6 M NaOH to cover the zinc dust and fd the evaparating dish half full. Next take a copper token and thoroughly clean it using steel wool. Set up a ring-stand, small iron ring, and a Bunsen burner. Set the evaporating dish and contents on a clay triangle an the iron ring. Heat the mixture until it is steaming and using tweezers place the copper token in the solution. When the chemical reaction is working you will see hydrogen gas being produced. Examine the token after a few minutes. When it is completely coated (silver in color), remove it, and wash it thor- oughly with water. Dry the silver token with a paper towel. Next, using apair of tweezers, hold the token in the outer cone of a Bunsen burner flame. I t will suddenly turn gold. Heat it for a few more seconds, remove it, and immediately wash it with water.

Explanation: Points to be discussed (1) The copper is plated with zinc, a surface coating (silver

color). (2) When the token is heated, the zinc diffuses in between the

copper atoms to form brass (gold color). Part 2: ''Nylon Rope Trick" Procedure: Nylon can he prepared by mixing hexanediammine and

adipyl chloride. Place 20 ml of 5% hexanediammine (aqueous solution) and 20 ml of 5% adipyl chloride (organic solution) into separate 50 ml beakers. Pour the adipyl chloride into a 150-ml heaker. Next, carefully (slowly) pour the hexanediammine on top of the adipyl chloride solution. Make sure that 2 phases are formed. Using a pair of tweezers the nylon can be picked up a t the interface of the 2 solutions. Twirl it around the tweezers until the nylon is no longer produced. Rinse the nylon thoroughly in alcohol and then in water. Squeeze it dry between paper towels.

Explanation: The following points shiould be discussed: (1) The concept of polymerization. . ; (2) Why there are two phases in the beaker. (3) The properties of nylon.

428 Journal of Chemical Education