Sulphuric acid
Sulfuric acid (alternative spelling sulphuric acid), also known as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is soluble in water and is synthesized in reactions that are highly exothermic.
Its corrosiveness can be
mainly ascribed to its strong acidic nature, and, if at a high
concentration, its dehydrating and oxidizing properties. It
is also hygroscopic, readily absorbing water vapor from
the air. Upon contact, sulfuric acid can cause
severe chemical burns and even secondary thermal burns; it is
very dangerous even at lower concentrations.
Sulfuric acid is a very
important commodity chemical, and a nation's sulfuric acid production is a good
indicator of its industrial strength. It is widely produced with different
methods, such as contact process, wet sulfuric acid process, lead
chamber process and some other methods.
Sulphuric
acid is probably the most important of all chemicals,
because of its extensive use in a very large number of manufacturing operations. Of the immense quantities made yearly, the greater part does not come upon the market; for, being expensive and difficult to ship, consumers of large amounts generally make their own acid.
The commercial grades of acid have special names. A moderately strong acid (50°_55° He.), such as condenses in the lead chambers, is known as "chamber acid." It contains from 62 to 70 per cent of H2S04, and is strong enough for use in the manufacture of fertilizer, and for other purposes requiring a dilute acid. By concentrating this chamber acid, an acid of 60° Be. is obtained, containing about 78 per cent of H2S04> which is sufficiently strong for most technical uses. Further evaporation in platinum or iron pans yields an acid of 66° Be., containing 93.5 per cent of H2S04, and known as oil of vitriol. Faming or Nordhausen acid, which is still more concentrated, is prepared by special means. It is essentially a solution of sulphuric anhydride (S03) in sulphuric acid. This is the acid which was prepared by the alchemists in the Middle Ages.
In about the year 1740, Ward, an Englishman, began to make sulphuric acid on a moderately large scale. He burned sulphur and nitre (KNO3) together, and condensed the vapors in glass vessels containing a little water. The dilute acid so formed was then concentrated in glass alembics or retorts. In this way all acid was produced at a lower price than the fuming acid could be made. and the industry was soon established on [t commercial scale. The reactions involved ill Ward's process are the bases of the method now in use; this consists in bringing together, under suitable conditions, sulphur dioxide, oxygen, and water as steam, in the presence of certain oxides of nitrogen. The latter probably act as carriers of the oxygen, causing it to unite with the sulphur dioxide and water to form the acid.
because of its extensive use in a very large number of manufacturing operations. Of the immense quantities made yearly, the greater part does not come upon the market; for, being expensive and difficult to ship, consumers of large amounts generally make their own acid.
The commercial grades of acid have special names. A moderately strong acid (50°_55° He.), such as condenses in the lead chambers, is known as "chamber acid." It contains from 62 to 70 per cent of H2S04, and is strong enough for use in the manufacture of fertilizer, and for other purposes requiring a dilute acid. By concentrating this chamber acid, an acid of 60° Be. is obtained, containing about 78 per cent of H2S04> which is sufficiently strong for most technical uses. Further evaporation in platinum or iron pans yields an acid of 66° Be., containing 93.5 per cent of H2S04, and known as oil of vitriol. Faming or Nordhausen acid, which is still more concentrated, is prepared by special means. It is essentially a solution of sulphuric anhydride (S03) in sulphuric acid. This is the acid which was prepared by the alchemists in the Middle Ages.
In about the year 1740, Ward, an Englishman, began to make sulphuric acid on a moderately large scale. He burned sulphur and nitre (KNO3) together, and condensed the vapors in glass vessels containing a little water. The dilute acid so formed was then concentrated in glass alembics or retorts. In this way all acid was produced at a lower price than the fuming acid could be made. and the industry was soon established on [t commercial scale. The reactions involved ill Ward's process are the bases of the method now in use; this consists in bringing together, under suitable conditions, sulphur dioxide, oxygen, and water as steam, in the presence of certain oxides of nitrogen. The latter probably act as carriers of the oxygen, causing it to unite with the sulphur dioxide and water to form the acid.
Comments
Post a Comment