The Acid/Carbonate Reaction

Acid/Carbonate Reaction

Acid-carbonate reactions are a specific type of acid-base chemistry.
These reactions occur when an acid reacts with a carbonate or bicarbonate to produce carbon dioxide, water and a salt.
- General reaction: Acid + Carbonate -> Salt + Water + Carbon Dioxide.
An example is the reaction of hydrochloric acid (HCl) with sodium carbonate (Na2CO3):
- 2HCl + Na2CO3 -> 2NaCl + H2O + CO2.
The carbon dioxide formed can be tested by using lime water. If carbon dioxide is present, the lime water turns cloudy.
An important note about these reactions is that they only fully happen if the carbonate or bicarbonate is a component in a solid compound. That is because an acid and carbonate in solution form a buffer.
These reactions are used in real life for a variety of purposes, including baking (baking soda is a bicarbonate), relief from heartburn (antacids are often carbonates or bicarbonates), and environmental chemistry (the reaction between carbon dioxide and water forms a weak acid).