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A Laboratory Outline of General Chemistry
A Laboratory Outline of General Chemistry Author:Alexander Smith Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: mercury in the tube. Disconnect the T tube, leaving the clip on the flask closed. Open this under water, equalize the levels, close the clip and weigh. Ascertain... more » the height of the barometer (p). Subtracting the weight of the flask (known) from the above weight gives the volume of water which entered. Subtracting this volume from the known total volume (d), we get the volume (c) of the air which partially filled the flask at atmospheric pressure (p) and completely at the reduced pressure (p'). Get (p') by subtracting the height of the mercury from (p). Boyle's law states that c: d :: p': p. Calculate (d) from (c), (p') and (p) by this formula and compare with the value of (d) observed. CHAPTER III. CHARACTERISTICS OF CHEMICAL CHANGE. i. Qualitative Study Of Chemical Change. a. Fit up an aspirator, attach to it a piece of hard glass tubing 20 cm. long, close the other extremity of this with a stopper fitted Fig. 3 with glass tube, rubber tube and clamp, and provide the other tubes and beaker all as shown in Fig. 3. The stopper of the aspirator should be of rubber. Test the apparatus and see that it is perfectly air-tight before proceeding further. Weigh out roughly into a CHEMICAL CHANGE % 7 porcelain boat about I gr. of powdered iron, which should be dried previously by heating it gently in a test-tube. Examine the physical properties of the iron and note the results. Place the boat in the middle of the tube. Fill the aspirator to the neck with water and put the tubes in position, without, however, finally inserting the stopper. Displace the air in the hard glass tube with a gentle stream of oxygen from the cylinder of compressed oxygen, and then press the stopper home and pass in more oxygen until most of the water has been driven over into the large bea...« less