alcohol (C2H50H);warm water; 8 test tubes; a test tube rack;a test tube
holder;a glassrod;an alcoholburner;andpaperand pencil.
Follow this procedure:Take a tiny pinch of each powdered or crystalline
chemical and taste it. (See page 27 forprocedureon tasting chemicals.) Then
putt teaspoonfulof sodium chloride in the first test tube,! teaspoonfulof
magnesium sulfate in the second test tube, and so on until you havetteaspoon-
fulofone powdered or crystalline chemical in each of the first 7 test tubes. Then
putIteaspoonfulof alcohol into the eighth test tube. Now add Itablespoonful
of water to the contents of each test tube. Taste a speck of the alcohol and water.
Write in thedatafor the first three entries of adatasheet, drawn up like this:
No.ofTestTube 1 2 3 4 5 6 7 8
Contents NaCI MgSO CHaCOOC.HaBOaCa(OH)aClIH 210 UCuSOCaH.OH
H,COOH
Appearance
beforedissolving
Descriptionof
taste
Appearanceof
solution
Appearanceafter
evaporation
Descriptionof
tasteGentlyheat each tube inturnover the alcoholburneruntil its contents begin
to boil. CAUTION: Remember to keep the mouth of the tube pointedaway
from your face and at a slight angle.Continueto boil each one, except the
eighth one until all the water is gone. As itdisappearsfrom each one, taste