Gas evolution reaction
A gas evolution reaction is a chemical reaction in which one of the end products is a gas such as oxygen or carbon dioxide. Gas evolution reactions may be carried out in a fume chamber when the gases produced are poisonous when inhaled or explosive.
- Zn + 2 HCl → ZnCl
2 + H
- In this example, hydrogen gas in diatomic form is released.
- A replacement reaction where gaseous hydrogen chloride and fluorine gas react to release diatomic chlorine gas (because fluorine is more electronegative):
- 2 HCl + F
2 → 2 HF + Cl