Edlted by:
HARRIET FRIEDSTEIN Monroe High School Rochester. NY 14607
Suggesllon for our Readers Are you aware that you may preview any material from the A-V producers? Write the suppliers for their catalogs or ask your librarian or resource reacher what is alreadv available in your school. T h e companies will usually ship the material to you for a 15-day or 30-day trial period a t which time sou may keep the set for payment or return it. You must pay;he return postage, so he sure that there is money in your budget for that. This method is an excellent wav to avoid orderine items that turn out to be less useful thaneanticipated.
cludes a summaw of each of the filmstrips and suaestions for materials and equipment that would b e needed for thirty students. This is not as precise a list as those that usually accompany lab manuals. You will therefore need to experiment to he sure that you have the proper chemicals and equipment, before you check out the p&idures in your own lab&atory setting.
-
No. I-Introduction to the Chemistry Laboratory (Part I) The fmt f h t r i p introduce some basic laboratory equipment and its use. It includes the balance, graduated cylinders, flasks, Bunsen burners, etc. Filtering techniques are shown in detail. Since this is a reissue of an earlier filmstrip the term "centigrade" is used in lieu of "Celsius." No. 2-Introduction to the Chemistry Laboratory (Part II) The use of a crucible is demonstrated as well as glass handling, bending, and fire polishing. An asbestos pad is show) as the vehicle for hot glass which will require an explanation on the part of the teacher since asbestos is no longer recommended for use in the chemistry Laboratory. No. 3-Measurement in Chemistry This filmstrip instructs the student in the use of the balance and volume measurements, with the goal being the calculation of the density of water and other samples. The student is also asked to heat a beaker of water and to graph the temperature versus time in this process.
This is a series of filmstrips that can be used in lieu of alab manual. I have. however. found some of these lackina in detail: they may, therefore, need to be supplemented. his series of 30 filmstrips is a re-release of a set produced by Encyclopedia Britannica which were circulated from 1963 to 1976. Check your material before you order to avoid duplication. The suggestion from the producer is that the teacher remain a t the projector as members of the class work in the lab. I find this unrealistic and very unsatisfactory. The lab instructor needs to move about the class; the lighting necessary for a laboratory experience is generally not satisfactory for projector viewing and because the students do not work a t an equal pace, they are not a t the same place in the procedure a t the same time. The use of a "Study Mate" a t each lab station would work t o better advantaee. But unless vou run a completely independent lab, this &am that you need several sets of these filmstrins. The cost of disoosahle lab manuals mizht make this a viabie alternative since this can he used from G a r t o vear. Another use of this series would be as a meview or reGiew. This, however, would not he my preference; but i t is a suggestion. In general, the pictures are very precise and each one is captioned in a clear way. There is lack of detail on a few which appears to be the result of a few pictures being deleted. You may need to have some added material to go along with this set. The series is accompanied by a teacher's guide which in-
No. 4-Experiments with Subatomic Particles An experiment is demonstrated using the cloud chamber and the Geiger counter with a radioactive source. This filmstrip requires more teacher explanation since details are lacking. The second part demonstrates the use of spectroscopes to examine the flame of various solutions. No. 5-The Size of Molecules One drop of oleic acid in alcohol is added to a thin layer of chalk dust on water. The student is directed to calculate the thickness of the film and the distance between the centers of two adjacent carbon atoms. No. GCrystallizotion This filmstrip introduces an experiment to observe the characteristic shape and manner of growth of each of several crystalline substances [(NH1)2SO1A12(SOa)3.24infn201, copper sulfate nickel ammonium sulfate, and potassium dichromate are observed through a microscope. No. 7-Chemical Reactions Several chemical reactions are demonstrated in this filmstrip. Magnesium is ignited with the Bunsen flame. The equation for this reaction is shown. The decomposition of calcium carbonate is the next reaction. followed bv the addition of iron to a canner sulfatesolutian. To demonstrate the formation of an insoluble~. kcioitate. silver ni. trarr is nddrd too solution of ~udillmchloride. The student i i then shown a wries ufrmet~onsand arkrd r u e q h i n the equationi. No. 8-Energy of Reactions In this experiment, heat energy produced by several reactions is calculated. Sodium hydroxide pellets are added to a flask of water. The temperature of the water is recorded hefore and after the addition. The student is asked to calculate the number of calories. Then a weighed sample of sodium hydroxide pellets are added to hydrochloric acid, and the temperature is recorded before and after the addition. Temperatures are also recorded before and after the neutralization of equivalent amounts of hydrochloric acid and sodium hydroxide. The amount of heat produced in this process is then calculated.
Experiments in Chemistry TIME: FORMAT:
Teacher determined 30 color filmstrips in 3 sets Teacher's Guide included PRICE: $240 for the complete set SUPPLIER: Adrian Vance Productions Box 49210 Los Aneeles. CA 90049
for the latest audioThis feature will serve as aclearinehouse " visualmnte~nlnovnilabletorhrmistr~tracheri. I t r i l l include review by users resulting from nrlual exprrienccs in the clnssrcmn. If you nre intcrrsfed is assisting in rhis prucrss, send your name and address to the feature editor.
~~~
~~
~~~
~
Volume 57, Number 10, October 1980 / 731
No. 9--Bode's Law The usedmercury is pmhihit.4 in our clapsroom laboratory. Since its usr is the h a w for this filmstrip. 1 suygert this filmstrip he used as a visual demonstration. No. 10-Charles' Low Apparatus for determining the eifwt irf temperature m the volume of a gas ir s h o w ior the student to duplirntr and then uie to calculate the change in volume. No. II-Molar Volume of o Gas Potassium chlorate is added to heated manganese dioxide and then heated again in an elaborate set-up to determine the molar volume of oxygen. No. 12-Determination of o Formula Weighed amounts of iron and sulfur are added to a clean, dry crucible, heated, cooled, and reweighed. Based upon the weights obtained in this experiment, the student is directed to answer a series of questions with calculations. No. 13-Ionization In this experiment, the student examines the differences in the boiling paint elevation caused by non-ionic (sucrose) and ionic (sodium chloride and calcium chloride) substances. A voltmeter is used to show the presence of the ions. No. 14-Acids and Bases The indicators phenolphthalein, methyl orange, end litmus paper are used with several substances to determine whether the substance is an acid or a base. The concept of strong and weak acids is demonstrated through reactions with magnesium and aluminum. No. 15-pH The natural dye is extracted from red cabbage and is used as a standard of comparison with known and unknown concentrations of acids and bases. The student calculates the pH of each solution. No. 16-Hydrolysis The student examines the degree of hydrolysis of a number of substances based upon the standard dye made fom red cabbage. (Did you save this from the receding exoeriment? No? Neither did I!) A Eomnarison of strone add weak acidsand bases is demonstrated. Since t pH salt. hydrolyze in nater in $,aryingdegrees, t h e ~ t u d e n usesthe of the wlution determine th~sdegrzeo f hydrolyis. No. 17-Equiualent Weight The student determines the equivalent weight of magnesium and comnares this with the theoretical calculation. A little hit of dexteritv is needed in this procedure, but the students should be fairly experienced with laboratory techniques by this point. No. 18-Titration Using a oair of burets, the student is directed to set up a titration system.-some explanation may be needed as the types of L e t s shown may not correspond to what you have available. Phenolphthalein is used in the procedure here, but I use bromthymol blue in the actual titration with my students. No. 19-Reaction Rates Here is anexamole of a beautifullvdesiened , .. exoeriment that caused a pent deal of grief for me and my studenti. It looked simplcenough, will,nnd ir d:d. but nm,rdingto hl~l~hy.ifrr,mrthingcangowc,ng,it ~ 1 he experiment wnminer the effects of cntolys~s,trmpemnlre, and concentration on a reaction rate. Cobalt nitrate is added very carefully to bleach. If the experiment succeeds, it's great No. 20-Eouilibriurn I'om.sium thiwyannrs is added u, imn chloridesolurion and is wed nsa standnrd for various a~~hstanccrdemonstrating the common i m effect. ~~
.
~~
~
.
No. 21-Oridation-Reduction Reactions Metal replwr~nrntreactiuns involving m~tallicalwninum, wppcr. ma~nwium.and tint, and solutions ot rol,pw sulfate, magnesium suliatr. ~ i n nitrotr, r and hydmrhk,rir arid are i,bsrrved. No. 22-Oxidation-Reduction Titration A known concentration of iron (11) sulfate is titrated with a standardized potassium permanganate. No, 23-Electrochemistry Electrochemical and electrolvtie cells are the basis for these exoeriments involvine zinc-zinc sulfate solution and comer-conner ~~~~. --=. -~ sulfate solution. Thr second pnrt drmonxrote%the fomatimofa hase nt the ~;lrhodrusine: an elertrolyml salt d u t i o n and phendphrhalcin as an indicator. Several electroplating experiments are shown
..
~
~~~
~~
~
~
732 1 Journal of ChemicalEducation
~
~
~~
~~
~~
.
~~~~
~~
~
No. 24 to No. 29 These experiments involve the specific experimentation of the families of elements, the alkalis, alkaline earths, halogens, sulfur, boron and aluminum, iron and sulfuric acid. No. 30--Qualitatiue Analysis The classic techniques of qualitative analysis are shown. The advantage of the filmstrips is the colored pictures. The student can compare hisher results with a standard. The directions are not very exact and so if you use this, you will need tosupplement theinstruetions with mare detail. The ions tested indude: PbZ,Hgs2,Ap. Cr3, A13, Co2,NiZ,Fez, Mn2,Ba2,Cr2,Sr2inaddition to the negative ions: Co+-, C1-, Br-, I-, S O P , 5%-,and NOS-. The use of carbon tetrachloride is a no-no in our laboratory, and i t is used here in the testing of the halides. I have uuclined the thirty experiments. If t hi; type of a d would he urelul to yuu in conducting yourlahoratory you shuuld consider t h ~ s series Sinre the prlce i i stcep. Ire partirulnrly aware oirhe numhpr of filmvtrips that you can nrtually make nvoilablr to your students.
Your Turn We would like to include reviews of other material t h a t you are currently using in your classroom. Please feel free to send u s the review a n d we will add i t to t h e column.
