Question

give two exmple in which reaction gas involved​

Answer 1

A gas evolution reaction is a chemical reaction in which one of the end products is a gas such as oxygen or carbon dioxide.

A replacement reaction concerning zinc metal and hydrogen chloride:

Zn + 2 HCl → ZnCl

2 + H

2 (gas)

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

2 (gas)