NOTE 1

• Sulfuric acid (H2SO4)


  Colorless oily liquid and most abundant industrial use
• Sulfuric acid


  • Its strength as a strong acid is a key player in industrial processes
  • Acts as a dehydrating and oxidizing agent - accepts electrons from other substances
• Sulfuric acid production


  • Majority used in production of phosphate fertilizers - essential for agriculture and food security
• Widespread applications of sulfuric acid


  • Explosives
  • Dyes
  • Glues
  • Wood preservatives
  • Petroleum refining
• Molecular formula and structure of sulfuric acid

  (H2SO4) consist of one sulfur atom bonded to four oxygen atoms
• Physical properties of sulfuric acid

  • Color: clear, colorless, oily liquid
  • Odor: Odorless
  • Boiling point: 315-338 degrees Celsius
  • Melting point: 10.35 degrees Celsius
  • Density: 1.84 at 15 degrees Celsius
  • Viscosity: high due to intermolecular forces
  • Solubility: Completely soluble in water
  • Reactivity: Very reactive and corrosive
• Contact process for producing sulfuric acid

  1. Preparation of sulfur dioxide

  2. Preparation of sulfur trioxide

  3. Preparation of concentrated sulfuric acid
• Preparation of sulfur dioxide

  Sulfur dioxide is prepared by burning sulfur in the presence of excess air
• Preparation of sulfur trioxide

  Sulfur trioxide is formed when sulfur dioxide reacts with oxygen in ratio 1:1 @ 400 – 450 degrees Celsius and 1-2 atm (pressure) using vanadium pentoxide (V2O5) catalyst - reaction is reversible
• Preparation of concentrated sulfuric acid


  1. Sulfur trioxide formed is made to react with concentrated sulfuric acid

  2. Sulfur trioxide cannot be dissolved in water directly as it leads to the formation of fog

  3. Product obtained after this reaction is called oleum

  4. Oleum is then dissolved in water to obtain concentrated sulfuric acid
• Why contact process is most used

  • It is favored due to its efficiency in producing high quality sulfuric acid on a large scale
  • Operating cost is low and conversion rate is high
• Wet sulfuric acid process

  1. Generation of sulfur dioxide

  2. Oxidation of sulfurous feeds

  3. Catalytic conversion of SO2 to SO3

  4. Formation of sulfuric acid

  5. Cooling and condensation
• Advantage of wet sulfuric acid process

  • Its ability to produce high-concentration sulfuric acid without the need for separate sulfur-burning step required in contact process
  • Requires careful handling due to the reactivity of oleum
• Applications of sulfuric acid

  • Chemical manufacturing (production of various acids, synthetic detergent, pigments, dyes, and sulfate salts)
  • Laboratories (pH adjuster, dehydrating agent, catalyst, and electrolyte)
  • Metal processing (removes rust and carbon impurities in steel pickling)
  • Batteries (facilitate electron generation when combined with lead)
  • Cleaning products (due to its strong corrosive properties)
  • Agriculture and fertilizers (used to create inorganic phosphate fertilizers)
• Sulfuric acid


  A type of chemical compound that is widely used in industrial processes; known as a strong acid
• Strong acid


  Completely dissociates into ions when dissolved in water; sulfuric acid is an example of a strong acid
• Dehydrating agent


  A substance that can remove water molecules from other substances; sulfuric acid is an example of a dehydrating agent
• Oxidizing agent


  A substance that can accept electrons from other substances; sulfuric acid is an example of an oxidizing agent
• Step 1: Generation of sulfur dioxide


  Burning sulfur or sulfur-containing compounds in the presence of air to produce SO2 gas.
• Step 2: Oxidation of sulfurous feeds


  Mixing SO2 gas with additional air and passing it over a catalyst to oxidize it to SO3 gas.
• Step 3: Catalytic conversion of SO2 to SO3

  Using a catalyst to convert SO2 gas into SO3 gas, lowering the activation energy required for the reaction to occur.
• Step 4: Formation of sulfuric acid


  Absorbing SO3 gas in water to form sulfuric acid (H2SO4), a strong mineral acid.
• Step 5: Cooling and condensation

  Cooling and condensing the resulting sulfuric acid mixture to form concentrated sulfuric acid for storage and transportation.