A laboratory outline of general chemistry by Smith Alexander 1865-1922

Author:Smith, Alexander, 1865-1922. [from old catalog]
Language: eng
Format: epub
Tags: Chemistry
Publisher: Chicago, Kent Chemical Laboratory of the University of Chicago
Published: 1899-03-25T05:00:00+00:00

Digitized by LjOOQIC

SULPHUR

First heat the pyrite in a very gentle stream of air until the sulphur burns. Then warm the nitric acid and divert part of the ail current so that it may carry over a little of the vapor of the acid. Keep the supply of sulphur dioxide going continuously. Repeat the introduction of nitric acid at intervals, whenever the disappearance of the red fumes in the bottle shows that a further supply is needed.

After a crust of crystals (?) has formed in the bottle (there may be considerable delay before crystallization starts), withdraw the gases from the interior by means of the pump. Detach the bottle, add 4-5 c.c. of water and wash down the crystals with it. Describe all that happens. If more of the product is required, the apparatus may be connected up again and a further supply of sulphur dioxide drawn into the bottle and subsequently more nitric acid vapor can be added. Finally any remaining crystals may be decomposed by water.

Filter the liquid in the bottle through a very small filter paper into a dish, rinsing the bottle with 2-3 c.c. of water, and evaporate on the sand bath [Hood] until the liquid begins to fume (?). • This will remove any nitric or nitrous acid that it may contain. Use the result for b»

b. Dilute the product from a by adding it to 2-3 volumes of water. Test the solution with litmus paper (?). In one-third of it place a piece of zinc or iron (?), To a small part add barium chloride solution (?). With the remainder make marks on a piece of paper by means of a match dipped in the liquid. Put the match and the paper on a radiator to dry (?).

c, [Hood]. Take 2-3 c.c. of concentrated sulphuric acid in a test-tube. Suspend a thermometer so that the bulb is completely immersed in the acid. Heat the contents of the tube by means of a small flame and note the temperature at which any effect (?) is observed and that at which it is conspicuous. Be careful not to wash out this tube until the acid has cooled.

6. Sulphates. Place some cupric sulphate in a hard glass tube and heat strongly with the blast-lamp after all the water has been

Digitized by LjOOQIC

Digitized by LjOOQIC

Digitized by VjOOQIC

driven off (?). Recall action of heat on gypsum (Chap. VII, 3,^). Classify sulphates in accordance with this distinction [R],

7. Sulphur dioxide.

a. Heat a piece of sulphur and a piece of charcoal with concentrated sulphuric acid in separate test-tubes. Notice the odor of the vapor. What property of sulphuric acid prevails in this case ? Recall Chap. X, 2, a and compare.

* Give a list of the properties of sulphuric acid which have been illustrated in 5, b and 7.

b, [Hood], Prepare a flask fitted like that in Fig. 6 and two gas washing bottles like that in Fig. 8. If 8 is omitted, the second bottle will not be required. Twist up

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.