Tested Overhead Proiection Series Compiled by HUBERT N. ALYEA
Princeton Univerritv
19. GROUP VI. THE SULFUR FAMILY
inch strips of cellophane film into it to coat the film with the gelatin.
F. Oxy-Acids of Sulfur and their Salts
Afaterials: Strips of gelatin soaked in 1 I.
in Tandem Bottles
To show: Reaction of powdered antimony with heated halogens.
Procedure: Project the three bottles standing in a tray of very hot water, bottle 1 filled with C12gas, bottle 2 containing a drop of liquid Br2, bottle 3 containing 3 flakes of Is. Darken room. Squirt Sb powder from a medicine dropper into each; turn off projector lamp as each is tested.
KBr I. -.
Displacement of Br- by CL, and of I- by
Preparation of SD-592: See figure. The bottles are 2-02 wide-mouth, clear-glass, square bottles fastened in tandem. Bottle A is filled with Clp gas; bottle B contains 10 ml IiBr-aq 20 ml CCL, bottle C contains 10 ml KI-aq 20 ml CClr.
+
+
Observations: There is more violet reaction in chlorine then in bromine, and hardly any reaction in iodine. A little light is given off in each case but is scarcely projectable. Dem. 590-Displacement
in a Horizontal Tube
To show: The relative activities of chlorine, bromine an iodine. Materials: chlorine gas, NaI, IiBr, glass wool, alcohol burner, 10 mm glass tubing 20 cms long. Prepa~ation: Push loose plugs of glass wool one-third the way from each end of the glass tubing. I n one end pack about 5 g of moistened IiBr, and in the other 5 g of moistened NaI. Support the tube on the stage of the projector, horizontally, so that the NaI is over an alcohol burner. Insert a one-hole stopper in the I
