CIS
THEORY AND PRACTICE OF ENGINEERING.
Book II.
Sulphuric Acid is a limpid, colourless, and inodorous liquid , and has great chemical powers,displacing most other acids ; it is decomposed by several metals, which become oxidised,and evolve sulphurous acid. When the metals are dissolved in diluted sulphuric acid, thewater only is decomposed, and the oxygen, being transferred to the metal, forms a metallicoxide, which unites with the sulphuric acid to form a sulphite, whilst the hydrogen isevolved. The specific gravity of sulphuric acid is 1-84. Liquid sulphuric acid is a com-pound of one atom of dry or anhydrous sulphuric acid, and one of water.
Anhydrous Sulphuric Acid. — When caustic lime or baryta is heated in its vapour theybecome ignited, and are converted into sulphates.
Sulphur
- 1
16
40
Oxygen
- 3
24
60
1
40
100
The common or liquid sulphuric acid
is composed of
Dry sulphuric acid -
- 1
40
81
Water
- 1
9
19
1
49
100
Sulphuretted Hydrogen Gas , under a pressure of seventeen atmospheres, at 50°, takes aliquid form ; it has a peculiar fetid odour, and is so diffusible that a very small portionescaping is sufficient to be perceptible in a large space. Its specific gravity, as compared
with air, is 1T7 to 1 ; and compared36 grains.
with hydrogen, as
17 to 1.
100 cubic inches weigh
Sulphur
- 1
16
94-1
Hydrogen -
- 1
1
5-9
1
17
100-0
The decomposition of the sulphurets is caused by exposure to the atmosphere; theoxygen combines with the metals to form an oxide, and the sulphur to form sulphuricacid.
Selenium is a brittle, solid, opaque body, of a metallic lustre, resembling lead in itsaspect; it has a ruby colour; its specific gravity is 4*32; it becomes semi-fiuid at atemperature of 212°, and boils at 650°.
Oxide of Selenium ,— selenious oxide.
Selenium - - - I
Oxygen - - - 1
-
40
8
83-3
16-7
1
48
100-0
Selenious Acid.
Selenium - - - 1
Oxygen - - - 2
_
40
16
71-43
28-57
1
56
100-00
Selenic Acid is a colourless liquid, which, at a temperature of 554°, is rapidly resolvedinto selenious acid and oxygen ; it has a strong attraction for water, and when mixed withit evolves great heat.
Selenium - - l
Oxygen - - - 3
-
40
24
62-5
37-5
1
64
100-0
Selenium combines with hydrogen, nitrogen, sulphur, and phosphorus.
Phosphorus is solid, semi-transparent, colourless, or of a light yellow tinge; it shines inthe dark, and, when pure, its specific gravity is 1*770. It is insoluble in water, and out ofthe contact of air it melts at 105°.
Oxide of Phosphorus.
Phosphorus - - 3
Oxygen - - - 1
-
48
8
85-78
14-22
1
56
100 00