The reaction of sulfur trioxide gas (SO₃) and sodium hydroxide (NaOH) is a neutralization reaction that produces sodium sulfate (Na₂SO₄) and water (H₂O). Here's the balanced chemical equation:

SO₃ (g) + 2 NaOH (aq) → Na₂SO₄ (aq) + H₂O (l)

Explanation:

* SO₃ (g): Sulfur trioxide gas is a strong acidic oxide.

* NaOH (aq): Sodium hydroxide is a strong base.

* Na₂SO₄ (aq): Sodium sulfate is a salt formed by the reaction of the acid and base. It dissolves in water to form ions.

* H₂O (l): Water is formed as a byproduct of the neutralization reaction.

Important Note:

This reaction is highly exothermic, meaning it releases a significant amount of heat. It should be performed with caution, preferably under controlled laboratory conditions.