Haber Process — Industrial Importance:

• Produces ~175 million tonnes $NH_{3}$/year globally
• $NH_{3}$ is the feedstock for fertilisers (urea, ammonium nitrate), explosives (via $HNO_{3}$), plastics
• Without the Haber process, approximately half the world's population could not be fed (fixed nitrogen in fertilisers)
• Fritz Haber received the Nobel Prize in Chemistry (1918)

Ostwald Process — Industrial Importance:

• Converts $NH_{3}$ to $HNO_{3}$ for fertilisers (ammonium nitrate), explosives (TNT, dynamite), nylon synthesis
• First step (Pt/Rh at 500°C) is capital-intensive — catalyst is expensive
• NO produced in Step 3 is recycled → high atom economy

CO Toxicity — Environmental/Medical:

• Source: incomplete combustion of organic material (cars, fires, heaters)
• Binds Hb 200× stronger than $O_{2}$ → carboxyhaemoglobin → tissue hypoxia
• Treatment: 100% $O_{2}$ (or hyperbaric $O_{2}$) to compete with CO for Hb binding
• CO has no smell or colour → "silent killer"

Zeolites — Catalytic Applications:

• Molecular sieve: separates molecules by size ($N_{2}$ from $O_{2}$, water removal from gases)
• Ion exchange: water softening (replaces $Ca^{2+}$/$Mg^{2+}$ with $Na^{+}$ in domestic water softeners)
• Cracking catalyst: ZSM-5 zeolite cracks long-chain hydrocarbons in petroleum refining

Greenhouse Gas:

• C$O_{2}$ (from Group 14) is the principal anthropogenic greenhouse gas; traps infrared radiation in atmosphere
• $N_{2}$O (from Group 15) is a potent greenhouse gas (298× stronger than C$O_{2}$ over 100 years)

Silicones — Applications:

• Water-repellent coatings, medical implants, caulks, high-temperature lubricants
• Biocompatibility makes them suitable for prosthetics and contact lenses