Here's how to balance the chemical equation for the decomposition of ammonium nitrite (NH₄NO₂) into nitrogen gas (N₂) and water (H₂O):

Unbalanced Equation:

NH₄NO₂ → N₂ + H₂O

Balancing Steps:

1. Nitrogen (N): There are 2 nitrogen atoms on the product side (N₂) and 2 on the reactant side (NH₄NO₂), so nitrogen is already balanced.

2. Hydrogen (H): There are 4 hydrogen atoms on the reactant side (NH₄NO₂) and 2 on the product side (H₂O). To balance hydrogen, place a coefficient of 2 in front of H₂O:

NH₄NO₂ → N₂ + 2H₂O

3. Oxygen (O): There are 2 oxygen atoms on both the reactant side (NH₄NO₂) and the product side (2H₂O). Oxygen is balanced.

Balanced Equation:

NH₄NO₂ → N₂ + 2H₂O