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A Laboratory Outline of College Chemistry
A Laboratory Outline of College 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: CHAPTER II. CHARACTERISTICS OF CHEMICAL PHENOMENA. 8. Qualitative Study of Chemical Phenomena. a. Rub a pinch (about 0.5 g.) of powdered roll sulphur wi... more »th a very small globule of mercury (use the dropper) in a mortar (?). When the mass has been intimately ground together for about five or ten minutes and no particles of mercury are longer observable, place it in a dry test-tube and add about 3 c.c. of carbon disulphide [CARE! Keep away from flames], a solvent for the free sulphur. Shake well (do not apply heat) and then pour off the clear solution into the sink [hood. Note 25, below]. Repeat, shaking well and pouring away the clear liquid. Continue this operation until a sample of the decanted liquid fails to give any sulphur by spontaneous evaporation upon a watch-glass. What is the product remaining in the tube [R 535]? By means of a few c.c. of carbon disulphide wash this product out upon a filter paper [Note 24, below] and allow it to dry. To show the composition of this substance place it in a small, clean, dry test-tube and heat strongly over a flame. What odor is noticed at the mouth of the tube? What product is found to sublime upon the walls of the test-tube? Rub the sublimate with a glass rod (?). What evidence of chemical change have you noticed in the above experiment? The mortar may be cleaned by placing in it a few drops each of hydrochloric acid and of nitric acid. Note 24. — Cut from a sheet of filter paper a piece 7 cm. (3 inches) square. Fold the square twice in directions at right angles to one another, so as to obtain a square of one-fourth the previous area. Cut off the loose corners with scissors so that a quadrant is formed. Open the folded paper so that a cone is produced (Fig. 6), and place the cone in a dry glass funnel. Smaller or la...« less