Which gas will be produced when you remove limescale with vinegar?

When vinegar (CH3COOH) is used to remove limescale (calcium carbonate, CaCO3), it undergoes a chemical reaction to produce carbon dioxide gas (CO2). The reaction between vinegar and limescale can be represented as:

CH3COOH (vinegar) + CaCO3 (limescale) → Ca(CH3COO)2 (calcium acetate) + H2O (water) + CO2 (carbon dioxide gas)

As vinegar comes into contact with limescale, the acetic acid in the vinegar reacts with the calcium carbonate, breaking it down and forming calcium acetate, water, and carbon dioxide gas. The carbon dioxide gas produced during this reaction is responsible for the fizzing and bubbling action that is observed when vinegar is used to remove limescale.