Answer: N 2 and H 2 (using Fe catalyst, high pressure, 400-500°C).
- A N<sub>2</sub> and H<sub>2</sub> (using Fe catalyst, high pressure, 400-500°C)
- B N<sub>2</sub> and O<sub>2</sub> combined catalytically over a platinum gauze
- C CH<sub>4</sub> and N<sub>2</sub> reacted directly at moderate pressure
- D NH<sub>3</sub> itself recycled through a secondary catalytic loop
Correct answer: A. N<sub>2</sub> and H<sub>2</sub> (using Fe catalyst, high pressure, 400-500°C)
Explanation: The Haber process: N<sub>2</sub> + 3H<sub>2</sub> ⇌ 2NH<sub>3</sub> (Fe catalyst, 150-200 atm, 400-500°C).
Each water molecule's O-H bonds (covalent, solid) can hydrogen-bond (dashed) to neighbouring molecules, forming an extended network responsible for water's unusually high boiling point and density anomaly.
Concept context
The simplest and most abundant element in the universe. Study its unique position in the periodic table, isotopes (protium, deuterium, tritium), properties of water and hydrogen peroxide, and industrial uses.