chemistry experiments for children

(lily) #1

Attachone end of a 4-inch piece ofcopperwire to theoutsideterminalof the
same dry cell.
Attachthe free endofthis 4-inch piece of wire to thecentralterminalof the
second dry cell.
Attachone endofthe second 12-inch pieceofwire to theoutsideterminal
ofthe second dry cell.
Attachthe second pieceofaluminum foil to the free end of this 12-inch
pieceofwire.
Nowfill thequartglassjarwith water. To make itconductelectricity, add
to it!teaspoonfulofsodiumchloride. Insertthe stripsofaluminumfoil as
thediagramshows and cover each one with a test tube filled with water. Let
theapparatusstandundisturbed.At the end of11-hours, observe the test tubes.
Results:Bubbles of gas began to appearand collectedaroundeach of the
stripsofaluminumfoil. The gas collected at the top of each test tube by the
principleofDownwardDisplacementof Water. Theamountof gas in one test
tubewasabouttwicethatin theothertest tube.
2.Performthese chemical tests todeterminewhat gases are in the test tubes.
First,light a wooden splint and extinguish the flame, allowing the tip to glow.
Putthe glowing splint into the test tube with less gas. Thenperformthe same
test with theothertest tube, butbe verycautious.Holdthe test tube upside
down,and with itsmouthpointingaway from you,puta glowing splint close to
the opening.
Results: When you putthe glowing splint into the first test tube, itburst
intoa bright white flame. Oxygensupportscombustion,so this provesthatthe
gas in the test tube was oxygen. When you put the glowing splint near the
openingofthe second test tube, there was a"pop"-thesoundof a small

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