What type of substances are metal carbonates categorized as?

Metal carbonates are categorized as bases because they can react with acids to produce salt, water, and carbon dioxide. This characteristic behavior is a defining property of bases; they typically neutralize acids.

In the context of metal carbonates, they consist of metal ions combined with the carbonate ion (CO₃²⁻). When a metal carbonate reacts with an acid, for example, calcium carbonate reacting with hydrochloric acid, it results in the formation of calcium chloride, water, and carbon dioxide gas. This neutralization reaction highlights their basic nature.

The associated properties of metal carbonates include their ability to increase the pH of a solution, making them basic in nature, which is why they are classified as bases rather than acids, neutral substances, or salts. While salts can be formed from the reaction of a metal carbonate with an acid, metal carbonates themselves are not salts; they are the starting materials that react to form salts.