Tested Overhead Projection Series Compiled by HUBERT N. ALYEA Princeton University
Dem. 526-Sodium
17. NITROGEN CHEMISTRY
T o show: Oxidation of carbou by sodium uitratc
and NO%from Cu
+ HNO3
T o show: Dilute and conceutrated HKOa react differently with Coppcr:
+ +
+
+ +
SHN03(dil) -c 3 C ~ ( N 0 3 ) ~ ~ H z O 2 x 0 3Cu Cu 4HXOs(conc) Cu(NO& ~ H z O 2NOz
+
-+
Mate?,ials: Two 2-02 clear glass, squarc bottles; Cu wire or shavings, HX03-conc., HN03-dil. Procedure: Projcct the bott,les side-by-side, one-tenth full of Cu wire or shavings. Pour 10 ml of dil. HKO, int,o one bottle, and 10 ml of conc. H N 0 3 into t,he other bottle. Obscivalions: Vigorous reaction occurs with conc. HNOa; the bottle is filled with browu NO2 gas. With dil. HN03, colorless KO is evolvcd, issues from the mouth of the bottle whcre it interacts with air t o form brown NOZ. Dem. 524-Nifmgen
T o show:
+ Carbon
Experiment developed by Carl J . Mancuso.
D. Oxides of Nitrogen Dem. 523-NO
Nitrate
Dioxide
The preparatiou of NIOn e 2NOI
Procedui,e: I'lace 2 g solid iVTaNOlin the G-l generator chamber, cold water in the collection chamber, aud dil. HZSOd in the dropper. Project. Drop the acid upon the KaNO,. Obseiuations: Rrowu S O n is generated aud ciiu be caught in the gas holder. If the receiving watcr is warm, a furthcr reaction can occur, see Dem. .i20 ahovc.
Materials: wood splint, sodium nitrate, H-3 Pvocedure: Darken room. I'roject 5 g KaXO, in cult,ure tube in H-3. Heat very hot until molten. Blow out flame and immediately plunge burning splint iuto the molten NaN03. (CARE: keep face away) Obseruations: Brilliant flame Reference: Reaction:
STONE,C. H., J. CHEM. EDUC.,20,200 (1943). 2NaN03
+C
-+
2NaiYOz
Dem. 527-Fire-writing
+ COX t
with KNOs
Experiment developed by Carl J . Mancuso. T o show:
Burning of IiN03-soalicd paper
Afalerials: Thiu sheet of stiff paper, saturated I i S 0 3 aq, two plastic strips about 4 X '/* X in. Procedure: Draw in an unbroken line on a 4 X 4 sheet of paper the notation K N O I . 1,ct dry. Prop about '/,in. above the horizontal stage with t,he plastic strips. Touch a lighted match t o thc IiN03. At t,he end exhibit thc paper macro. Observations: The paper burns through, aud the formula TWO3 appears on the screcn.
2. ANALYTICAL
Dem. 528-Nitrafe
Ring Test
T o shox: Thc ring test for nitrates. Afalerials: KaNOa-aq, colic. HISOl, fresh I'eSOd-aq, mediciric dropper with stcm &in. long, H-3, :
