Which gas is released when carbonate reacts with acid?

Which gas is released when carbonate reacts with acid?

• A. Oxygen
• B. Hydrogen
• C. Carbon dioxide
• D. Nitrogen

Answer: (C)

When carbonate reacts with acid, carbon dioxide is released. The acid provides hydrogen ions that react with the carbonate to form carbonic acid, which quickly decomposes into carbon dioxide and water. A typical equation shows this: CaCO3 + 2HCl → CaCl2 + CO2 + H2O. Since CO2 is a gas at room temperature, you see bubbles as it escapes from the solution. Oxygen, hydrogen, or nitrogen aren’t produced in this reaction, so the gas released is carbon dioxide.

When carbonate reacts with acid, carbon dioxide is released. The acid provides hydrogen ions that react with the carbonate to form carbonic acid, which quickly decomposes into carbon dioxide and water. A typical equation shows this: CaCO3 + 2HCl → CaCl2 + CO2 + H2O. Since CO2 is a gas at room temperature, you see bubbles as it escapes from the solution. Oxygen, hydrogen, or nitrogen aren’t produced in this reaction, so the gas released is carbon dioxide.