Preparation, Handling and Storage of Sulphuric Acid
Also called Oil Of Vitriol, or Hydrogen Sulfate battery acid, Sulfuric acid is a dense, colorless, oily, corrosive liquid, which is soluble in water. A highly corrosive strong mineral acid, it is a key ingredient in chemical industries used in ore processing, fertilizer manufacturing, oil refining, waste water processing, and chemical synthesis. Denoted by the chemical formula H2SO4, sulfuric is highly caustic and has to be handled carefully.
Molecular formula - (H2SO4)
Molar mass - (98.079 g/mol)
Appearance - (Clear, colorless, odorless liquid)
Density - (1.84 g/cm3, liquid)
Melting point - (10 °C, 283 K, 50 °F)
Boiling point - (337 °C, 610 K, 639 °F)
Solubility in water - (miscible)
Acidity (pKa) - (3, 1.99)
Viscosity - (26.7 cP (20 °C))
Sulfuric Acid is prepared by two main methods:
The Lead-Chamber Process: An industrial process, it was used in the 18th century for bulk quantities. The process involves sulfur and potassium nitrate, ignited in a room lined with lead foil and the floor covered with water. Potassium Nitrate being an oxidizing agent, oxidizes the sulfur to sulfur trioxide, which reacts with water to give sulfuric acid.
The Contact Process: used in contemporary times, consists of four stages and uses Vanadium Oxide as the catalyst. Firstly Sulfur is combined with oxygen, which is introduced to excess of oxygen in the presence of catalyst Vanadium Oxide. Sulfur Trioxide so formed is sulfuric acid which yields disulphide acid, which is treated with water to give highly concentrated sulfuric acid.
Potential Heath Hazards
Eyes: Exposure to eyes causes eye burns, with long-term exposure even causing chemical conjunctivitis and corneal damage.
Skin: Sulfuric acid is highly caustic and contact with skin severe skin irritation, skin burns and dermatitis. Burns from sulfuric acid are potentially more serious than those of other comparable strong acids, as not only does it cause chemical burns but also secondary thermal burn which poses additional tissue damage due to the heat liberated by the reaction with water.
Inhalation: Inhalation of particulates is very toxic and may cause severe irritation or chemical burning of the respiratory tract. Symptoms include sore throat, coughing, shortness of breath and delayed lung edema. Inhalation at high concentrations may even lead to CNS depression and asphyxiation.
Ingestion: Ingestion of the compound may cause irritation, and permanent damage to the digestive tract. Ingestion in large quantities may cause perforation of the digestive tracts and severe gastrointestinal tract burns and may be fatal.
Chronic: Prolonged or repeated inhalation may cause kidney and lung damage. Prolonged or repeated skin contact may cause dermatitis. Prolonged or repeated inhalation may cause nosebleeds, nasal congestion, erosion of the teeth, perforation of the nasal septum, chest pain and bronchitis. Prolonged or repeated eye contact may cause conjunctivitis. May cause fetal effects. May cause cancer in humans. Effects may be delayed. Laboratory experiments have resulted in mutagen effects. May cause schematic heart lesions.
Handling and Storage
Handling: The compound needs proper handling as unregulated contact may have damaging effects on vital organs of the body. Avoid breathing fumes and vapor, and wear chemical-resistant clothing, proper masks, safety goggles and gloves. Wash hands and contaminated clothing thoroughly after handling the compound.
Storage: Store away from direct heat or sunlight in a cool and well-ventilated place or a closed system.
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