Synthetic Inorganic Chemistry

HYDROBROMIC ACID

Materials: bromine, 40 grams = 12.5 cc. = 0.25 F.W.

red phosphorus, 7 grams.

sand.

broken glass.

Apparatus: 125-cc. separatory funnel.

300-cc. flask.

two 4-inch side arm U-tubes.

8-inch plain U-tube.

one 1-hole rubber stopper to fit flask.

4 solid rubber stoppers to fit small U-tubes.

one 1-hole rubber stopper to fit large U-tube.

glass delivery tubes as in diagram.

glass wool.

3 ring stands.

4-inch iron ring.

4 burette clamps.

145

FIG. 20
Procedure: After carefully studying the diagram (Fig. 20)
construct the apparatus. Place 6 grams of the red phosphorus,
12 grams of sand, and 6 cc. of water in the flask. The success of
this preparation depends very largely on the care with which the
phosphorus is spread out over the surface of the broken glass in
the small U-tubes. To this end mix 2 grams of the phosphorus
and 25 grams of the broken glass by shaking in a 300-cc. flask.