Answer:The Contact Process is a commonly used method for the manufacture of sulfuric acid. It involves several steps and the use of catalysts. Here's an overview of the process:
1. Sulfur Combustion: Sulfur (S) is burned to produce sulfur dioxide (SO2) gas according to the equation:
S + O2 → SO2
This step usually takes place in a furnace.
2. Sulfur Dioxide Conversion: The sulfur dioxide gas is then passed through a catalyst bed to convert it into sulfur trioxide (SO3). The catalyst commonly used is vanadium pentoxide (V2O5), which helps promote the conversion reaction:
2SO2 + O2 ⇌ 2SO3
This step occurs at an elevated temperature.
3. Absorption: The sulfur trioxide gas is then mixed with concentrated sulfuric acid (H2SO4). This mixture forms oleum (H2S2O7), also known as fuming sulfuric acid. The reaction is highly exothermic:
SO3 + H2SO4 → H2S2O7
4. Dilution: The oleum is then diluted with water to produce the desired concentration of sulfuric acid. The dilution process is carefully controlled to control the temperature rise due to the highly exothermic nature of the reaction.
H2S2O7 + H2O → 2H2SO4
5. Purification: The final step involves purifying the diluted sulfuric acid to remove any impurities. Common purification methods include filtration, sedimentation, and further distillation.
The Contact Process is efficient and widely used in industry due to its high conversion rates and the ability to produce sulfuric acid on a large scale. Sulfuric acid is a crucial industrial chemical with numerous applications, including the production of fertilizers, dyes, detergents, and various chemical processes.
Step-by-step explanation: