TOPS
a-Mum
6. IONIZATION, ELECTRICITY (Continued)
B. Production of Electricity Dem. 3 13-Magnesium
+ Acid Ringing a Bell
Device developed by LeRoy G. Hornbeck. To show: Electricity from Mg HC1 ringing a bell
+
Materials: A small 3-v electric buzzer, 6 N H2S04; Mg ribbon brightened by rubbing with steel wool, then rinsing it in water; 1.5-v battery, 4'/2 X l l / z X I-in. plastic tray. Speczal Device, SD-313: Change the wires on the 2-coil buzzer so they are in parallel, and adjust the tension on the contact so that the buzzer will operate on a 1.5 v flashlight battery. Fasten a small battery clip to one terminal and a 2-in. No. 18 Cu wire spiral to the other. Solder a thin piece of Cu wire as an extension to the armature, so that it can be seen upon projection.
Tested Overhead Proiection Series Compiled by
HUEERT N. ALYEA Princeton University
Dem. 3 14-Magnesium
+ Acid Lighting
a Bulb
Experiment developed by Leroy G . Hornbeck. To show: Electricity, generated from Mg flashes a photo-flash bulb.
+
acid,
Materials: Tiny M-2 photoflash bulb, 6 N HzSOI. X 1-in. plastic tray, Mg ribbon brightened 41/2 X 11/% with steel wool then rinsed with water. Special Device, SD-314, see Figure. Procedure: Make 3 loops of NIg around the fingers then clamp the bundle in the alligator clamp of SD-314. Project with the wires held just above the plastic dish a/4 full of 6 N acid. Suddenly lower the Mg ribbon and copper spiral into the acid. Observations: The bulb flashes; this can he seen clearly on the screen. The Mg continues to react vigorously, giving off Hz gas. Note:
NH&-aq e m be substituted for HxSO,.
Reference: VILLEAREAL, G . , J . Chem. Educ. 34, A481 (1957).
Procedure: Make three loops of Mg ribbon, and fasten in the battery clip. Project the device with the Cu spiral and Mg ribbon held just above the plastic tray 3/4 full of dil. H2S0,. Suddenly lower them into the acid.
+
-
+
Observations: Mg H+ Mg++ Hz. Bubbles of Hz arise, flow of electrons through the buzzer starts the armature vibrating. See next demonstration.
SD-314.
Mp f HCI Lighting a Bulb
Dem. 3 15-Couples
Without a Salt Bridge
Experiment developed by Robert Barnard. To show: Direction of flow and, qualitatively, the amount of voltage generated by couples. SD-313.
Mg f HCI Ringing a Bell
Special Device SD-316: Is SD-305a with battery. Volume 43, Number 7, July 1966
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