The importance of chemical reactions in industry
Every chemical production rests on a series of reactions, and the task of technology is to run them under the most favourable conditions. Reaction rate rises with temperature: for each 10 °C of heating the rate grows γ times (γ is the temperature coefficient), for example with γ = 2, going from 20 °C to 60 °C raises the rate 2⁴ = 16 times. A higher concentration of reagents also raises the rate: in 2NO + O₂ → 2NO₂, doubling the O₂ concentration doubles the rate, doubling the NO concentration raises it 2² = 4 times. A catalyst speeds up a reaction and is not used up. In reversible reactions chemical equilibrium is established; conditions are changed to shift it: for example, in N₂ + 3H₂ ⇌ 2NH₃ + Q, raising the pressure (4 volumes give 2 volumes) and removing the ammonia increase the yield; low temperature raises the yield but lowers the rate, so a catalyst (Fe), about 400–500 °C and high pressure are chosen. In sulfuric acid production 2SO₂ + O₂ ⇌ 2SO₃ runs with a catalyst (V₂O₅); for nitric acid ammonia is oxidised on a Pt catalyst: 4NH₃ + 5O₂ → 4NO + 6H₂O. The practical yield compared with the theoretical: η = m(practical)/m(theoretical) · 100 %. Scientists and enterprises in Uzbekistan work on mineral fertilisers, drug substances and polymers.
Make a table: “Process” (NH₃ synthesis, SO₂ → SO₃, NH₃ oxidation), “Catalyst”, “Temperature and pressure”, “Why these conditions?”. Industrial reactions cannot be run at school; they involve high pressure, high temperature and poisonous gases, so watch demonstration videos and diagrams with the teacher.