Synthetic Inorganic Chemistry

VOLUME OF HYDROGEN DISPLACED BY ZINC 29

Weight of flask and water grams
Weight of empty flask grams
Weight of water grams
Barometric pressure mm.
Temperature °
Vapor pressure (p. 353) mm.
Arrange the apparatus as shown in Fig. 11. Clamp a drying
tube in a vertical position with its larger end down. Fit this end
with a stopper through which passes a short glass tube. Connect
the latter by means of 18 inches of rubber tube, provided with a
pinch cock, with a funnel supported upright in a considerably
higher position than the drying tube. From the other end of the

DrytagTube

Burette Clamp

Rubber Tube

Small Flask

Large Fan

Glass .Elbow

FlG. 11

drying tube lead an 18-inch rubber tube to a trough. This tube

should have a right angle, 3-inch glass tube, attached to its end.

Inside the drying tube is to be placed the zinc. Obtain a rod of it

about 2.5 cm. long and 0.6 cm. in diameter. Clean and dry it, and

weigh it accurately. A short piece of twisted copper wire supports

the zinc in the tube. Pour water into the funnel until the whole ap-

paratus is filled, and close the pinch cock. When everything is

ready invert a 300-cc. flask completely filled with water, over the

end of the glass tube in the trough. Pour dilute hydrochloric acid

(6iV) into the funnel and allow it to pass the pinch cock until