Laboratory Preparation of Nitrogen (N₂)
Heating ammonium chloride with sodium nitrite · collected over water
Apparatus Required
- Round bottom flask (RBF)
- Thistle funnel
- Delivery tube
- Pneumatic trough
- Inverted gas jar
- Beehive shelf
- Bunsen burner
- Tripod stand + wire gauze
Chemicals Required
- Ammonium chloride (NH₄Cl)
- Sodium nitrite (NaNO₂)
- Water
Chemical Reaction
NH₄Cl + NaNO₂ → N₂↑ + 2H₂O + NaCl
Ammonium chloride reacts with sodium nitrite on heating to produce nitrogen gas, water and sodium chloride.
Key Points
- N₂ is colourless, odourless, tasteless
- Collected by downward displacement of water
- Neither burns nor supports combustion
- N₂ is slightly lighter than air
- It is relatively unreactive at room temperature
Safety Precautions
Wear safety goggles · Handle chemicals with care · Work in a well-ventilated area · Avoid inhaling gases directly · Use heat-resistant glassware.