Chemical reactions: acid and metal carbonate

A group of one carbon atom and three oxygen atoms bonded together is called a carbonate group. Metal carbonate + acid → salt + water + carbon dioxide The test for carbon dioxide gas is to bubble it through limewater as it turns the solution cloudy (milky). Rain water is usually a little acidic and when it is more acidic than normal it is called acid rain. Acid rain reacts with marble to produce a salt, water and carbon dioxide, using up some of the marble.