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.

Examples

• A replacement reaction concerning zinc metal and dilute sulfuric acid.

$\mathrm{Z}\mathrm{n}+\mathrm{H}{\phantom{A}}_2\mathrm{S}\mathrm{O}{\phantom{A}}_4(\mathrm{d}\mathrm{i}\mathrm{l})⟶\mathrm{Z}\mathrm{n}\mathrm{S}\mathrm{O}{\phantom{A}}_4+\mathrm{H}{\phantom{A}}_2\uparrow$

In this example, diatomic hydrogen gas is released. Dilute hydrochloric acid can be used in place of dilute sulfuric acid.

• A replacement reaction where gaseous hydrogen chloride and fluorine gas react to release diatomic chlorine gas (because fluorine is more electronegative):

$2\mathrm{H}\mathrm{C}\mathrm{l}+\mathrm{F}{\phantom{A}}_2⟶2\mathrm{H}\mathrm{F}+\mathrm{C}\mathrm{l}{\phantom{A}}_2\uparrow$

See also

• Gasogene
• Kipps apparatus
• Gas generator
• Thermal decomposition
• Oxygen evolution