Why the reaction stops quickly when sulphuric acid is added to marble chips?

When sulfuric acid is added to marble chips, a chemical reaction takes place in which the acid reacts with the calcium carbonate in the marble to produce carbon dioxide gas. This gas forms bubbles which can create a layer around the marble chips, limiting further contact with the acid and slowing down the reaction. Once the layer of gas forms, the reaction rate decreases, resulting in the rapid reaction coming to a halt.