What is N2? Important Knowledge for N2

1. Definition of N₂

N₂, commonly known as Nitrogen, or Nitrogen gas in English, is a common atom in the air, accounting for about 78% of air volume. N₂ has an atomic mass of 14 and an atomic weight also of 14, composed by two nitrogen atoms connected by a triple covalent bond. In nature, nitrogen does not exist as ions.

2. Properties: N₂

2.1 Physical properties of N₂: Nitrogen is a colorless, odorless, tasteless, and non-toxic gas. Notably, Nitrogen has a neutral pH, is non-corrosive, and non-flammable.

2.2 Chemical properties of N₂: Nitrogen is very chemically inert, not readily reacting with other substances due to its high covalent bond energy.

3. Common chemical equations involving N₂: Nitrogen reacts with metals, acids, and nonmetals under special conditions. Examples include:

• 3Fe + 4N₂ -> Fe₃N₄(metalreaction)
• Cu + 4HNO₃ -> Cu(NO₃)₂ + 2NO₂ + 2H₂O(acidreaction)
• N₂ + 3H₂ -> 2NH₃(nonmetalreaction).

4. Preparation of N₂

4.1 Laboratory preparation of N₂: Typically, in the laboratory, nitrogen is prepared from ammonia by heating it with iron powder.

4.2 Industrial preparation of N₂: In industry, nitrogen is obtained from air by separating air by cooling and compressing the air.