26 QUANTITATIVE ASPECTS OF CHEMISTRYMaterials: potassium chlorate, dry, powdered.
Apparatus: wash bottle (see p. 5).
6-inch Pyrex test tube with 1-hole rubber stopper.
600-cc. beaker.
pinch cock.
2.5-inch funnel.
iron ring and ring stand.
Bunsen burner.
burette clamp.
2 feet of rubber tubing.
Data Form:
(a) Weight of test tube + potassium chlorate.. grams
(6) Weight of empty test tube grams
(c) Weight of potassium chlorate grams
(d) Weight of test tube and contents after heat-
ing grams
(e) Weight of oxygen grams
(/) Weight of beaker + water grams
(g) Weight of beaker empty grams
(h) Weight of water grams
(i) Temperature °
(j) Barometric pressure mm.
(k) Vapor pressure (p. 353) mm.Procedure: Set up the apparatus as shown in Fig. 10. Clamp
the wash bottle in an inverted position. Attach a 2-foot piece of
rubber tube to the mouth piece of the wash bottle. Slip a pinch
cock over the tube, and insert a small funnel in the open end.
Raise the funnel to the position shown by the dotted lines in
Fig. 10. Pour water through the funnel, and fill the wash bottle
nearly to the top of the vertical tube. Close the pinch cock,
and replace the funnel with the capillary tip from the wash bottle.
Connect the other tube of the wash bottle to the Pyrex test tube
by means of an elbow tube and rubber connection. Open the
pinch cock and allow water to run out of the wash bottle into
the beaker. If the apparatus is tight the flow of water will stop
completely after a moment. Close the pinch cock, remove the
Pyrex test tube, dry it, and weigh it accurately. Place in it